Who thinks $5K speaker cable really better than generic 14AWG cable?

Doing a "blind test" in a store will not change the fact that cables make a difference. 

And, When you move some cables around, the sound will become fuzzy  after you move them, and the distinguishing characteristics of each cable is lessened to the point where they all sound alike. My Nordost and Shunyata are like this, and I’ve also owned Transparent’s top cables as well as MIT and XLO. 

HOWEVER, when I first started out, I was not knowledgeable enough to know to leave cables alone for an hour or two (yes, I’ve timed it myself, using Ella Fitzgerald and Nat King Cole albums, because voice will tell you everything you want to know) before playing. The fact that your second dealer (or the first one, for that matter), has tin ears, proves nothing.  A local dealer I know, (and his system is pretty expensive) has disappointing sound for something with ARC, Wilsons and Transparent. And the contours of the music, dynamically, tonally AND spatially??? It’s not in evidence in this system. Unbelievable almost, but true.
 
People use "the dealer says" as a substitute for saying, "The AUTHORITY stated..." Dealers don’t necessarily know music, you know. And they don't necessarily know how to set equipment up. There's more to it than plonking it down on a rack and playing, something that is routine now, but 30 years ago, the setups were more meticulous. Look at the audio shows: even THEY don't get everything set up right the first day of the show. 

If you’re going to test cords, take them home and install them yourself. On YOUR system. and then leave it alone for two hours and play it. Then change the cords, leave alone for a while again.
There are no shortcuts here. The differences among components - mostly amps and preamps - are more easily discernible than cables, because nothing is moving around in the amps and preamps, whereas, with cables, you’re stretching the cable and twisting them. I’ve NO idea what goes on inside, but I’ve owned the most expensive things around, and cables do not react well to being moved.

Your experiment was not truly a controlled experiment, not to mention blind tests are not a good way to determine quality. I see people on here who buy cables and complain it doesn't sound 'good'. Lets take Shunyata, since I know them best. There are people who buy Shunyata’s cables and after 40 hours comment on them and say, ugh, they’re dark. By now, any decent thread will inform you that Shunyata’s Zi-Tron cables will take around 400 hours before they lose their constricted sound, yet people write interviews based on 200 hours of play. I assume they don’t know not to write a review until the product is fully broken in and some products take that long (CJ with their Teflon capacitors, and anyone else who uses Teflon). Shunyata, incidentally, says, 200 hours, but in 14 years of having owned Shunyata products (speaker cables, power cords, interconnects), I have yet to find the component's fully burned in at 200 hours. BUT. They may use a different breaking method, although they champion "heavy" fans left on. 
I’ve bought expensive cables since 1986 and I can hear the differences among MIT, Transparent, XLO, Furutech, Goertz, Shunyata (I own many Shunyata cords and signal cables), Nordost (ditto). The only ones that sounded very alike were the Goertz and the Nordost, a finding that two Absolute Sound reviewers (one of them was HP) parroted when they did their review. HP said he wouldn’t be able to tell the difference between the two easily. However, he then added a caveat in this review: that you could hear much more easily the differences between the two cables IF YOU USED VINYL INSTEAD OF DIGITAL. A good point if one wants to get to the truth the fastest. I’ll guess your dealer used digital. Well, that’s no crime, but it led you to the wrong conclusion.
Cables a ripoff??? Well,yes, the pricing is obscene for many of the top brands. The upside? They do make a difference. Even my tin-eared friend hears that.
Your dealer’s setup sounds like it needs fine tuning. Do you know the components he used? Are you familiar with ALL of the components, because you're just guessing otherwise. Far too many dealers to not take time to set up their equipment flawlessly, and I include at least one of the legendary stores in New York, Lyric. The one time I went to audition an amplifier in there, it sounded flat-out horrible. Knowing Harry wouldn’t have praised it (the ASL Hurricanes) that highly if it wasn’t that good, I just bought the amps, instead, from another dealer and it was magical. So, if I’d gone by that test, I’d never have bought the amp. I knew Harry, so I knew if he said it was phenomenal, then it was.
With the equipment you have at home, you should be able to hear differences without much strain. Listen on your OWN system, AFTER the components are broken in. ALL of them. And find out how many hours your dealers have on components they use for demonstrations. Too many things are wrong in your premise, but especially ’The Great Cable Ripoff’ caper.

Anyone who know ANYthing about cables, knows that once you move them, it takes a while for them to ’settle’ again. A ’blind test’ done by switching cables out, one after the other, is the height of futility and absurdity.
It’s not the cable, it’s one’s level of sophistication and knowledge. Now that there are a zillion cable around, whereas there used to be only 3 or 4 top brands that dealers carried, people walk in and want to hear "X" or "Y" compared to each other, one right after the other. This is dumb, but not necessarily the consumer’s fault. The dealer fails to educate his client base and with the short attention spans people betray, it’s no wonder someone feels like this.

Clearly few people remember the Stereophile Carver Challenge, when Bob Carver tried to duplicate his amp to make it sound exactly like certain tube amps. As pointed out, it was absurd to expect people to be able to discern differences in a matter of seconds or minutes.
When I move my Shunyata cable around and listen - and voice is ALWAYS better, because most singers stand right at the mike. Wiat, let me qualify that: OLDER recordings with well-recorded singers (Ella, Nat King Cole, Sarah, Eileen O’Farrell, Callas, Leontyne Price), will do the trick. Using those recordings, I can move my cable and hear the loss of hard consonants (words ending in "d" or starting with "p" because, especially with a word starting in "P" the sound creates a sort of "aspirant." Just say the word "push" out loud: there is no way to say it without, literally, pushing air out of your mouth, whereas the word "thought" does not "push" air out. So, move the cable, play Ella Sings Cole Porter, or even music up to say, 1970, and you can easily hear the aspirant disappear. Leave it for an hour and try again. You will now hear the aspirant.

Cable are not rip-offs: people merely have incompetent dealers, more interested in selling than in educating their customers, and simply saying, "lets let this sit for 20 minutes or so" because the customer may simply leave.
Flowers don’t grow because you throw water on them: they take time. Nobody rushes a flower to bloom, or a foal to walk. They do it in their own time.
Cables also need TIME to settle. You don’t have to buy new ones to test this knowledge out: do it on your own system. Same with power cords (especially Shunyata because, I think, of the way the cable is woven. But I can hear it on my Nordost as well). And I buy from places where I can return the item if I don’t hear a sufficient increase in sonics. And many is the time I haven’t hard enough to warrant the purchase. But blaming the genre as a rip-off? You need better ears, and a knowledge of how live music sounds (or at least something that has not been multi-mixed at a console).
So, instead of "fake news," try acquiring something that you can put in your own system and do it the correct way. Insert. WAIT. Then listen.
Whereas, the listening experience used to be a relaxing one, when brick and mortar  establishments were the standard of the day - and dealers had actual knowledge - you could, assuming you knew anything - trust your ears. Now? The dealers are mediocre,  and their setups are poor. A nearby dealer has top of the heap electronics, and the worst setups, and yet he sells tons of ARC, Nordost, and others. Yet, he has no ears. I have a suck out around the lower treble, yet I can easily tell when something is wrong. In his setup,  it's ALL wrong. 
Bad setup will cancel out hearing what the equipment (including the cable) can do. Do you know the equipment well enough to assess the cable? One wonders.

Yes, Dynaquest, "cables need to settle." 
And your comparison with flowers is quite apt, since my mother was an expert flower grower. And anyone who with any gardening experience past a 3- year olds (apologies to the expert younger gardeners) would have told you, the soil around the flower needs to be left alone. Surely you know that when you plant even a lawn, you are not supposed to walk on it until well after the grass has grown a bit. Soil should not be tamped down. All you have to do is read the bag to learn that. It's not a mystery.
So, in essence, you've answered your own question, although I suspect  you didn't intend to. And it sounds like you have not experienced the higher priced spreads and their quirks. They have quirks. Shunyata, on their website, even shows diagrams of how the cable should not slump, but should be perfectly level at all points. 
At some point, novices need to listen to more experienced users before registering  disbelief. And, my training was: do the experiment yourself to see the results (did you skip high school chemistry?) You also skipped the experiment, as recommended above, didn't you? Naughty boy. You get an "F".

Oh, and  speakers need to be PERFECTLY level, too. Not 1/8" off. PERFECTLY. Small inflections, inner detail will disappear. So dealer's showrooms are not the last word in authority. I'm sure that will cause  you chuckles, too. All for the good.  After all, laughter is the best medicine, non? 

Just passing through here today (since I have one of those "expensive" cables for sale), and all I can say is: I’m not interested in converting anyone. Don't need to.
If Dynaquest cannot hear the difference, good for him. I can’t imagine who his dealer is, or how the difference can’t be heard: I can hear it even with my hearing loss.
But it’s certainly CHEAPER to NOT hear a difference, and believe me, I wish my hearing was  even poorer, too. I’d be quite a bit richer. Money-wise, but not music-wise.