The $27,900 disappointment? Wilson Audio Watt Puppy 8 issues.

I think you are missing the real point when describing design flaws with certain speakers. It is not an issue of the quality of the amp or what type of load the amp can drive. The simple fact is that lower impedance speakers are harder to drive, result in more distortion and quite possibly prevent the speaker from sounding as good as it could if the impedance were higher. 

...Or, they could sound better if reducing the impedance also reduces the Q resulting in a more linear response or reducing a peak.

To simplify, based on the impedance curves above, Wilson likes to parallel two 8 inch woofers in their Puppy cab which gives you a low impedance in some specific lower frequencies.  This seems to be done in all the models throughout the decades.  Obviously, Wilson and others like the way that makes the low frequency sound.  So, saying it is wrong to do that, is maybe looking at it in the wrong context...  For example, Wilson assuming that the customer will use an amp that can drive a 2.x ohm load for some specific lower frequencies may sound better to them than using a lesser quality amp and changing the woofers wiring/crossover to achieve a higher ohm load.  The context may be to take account the quality of the amp together with the speaker crossover/wiring -- Wilson may be looking for that little additional edge in bass sound from a total system.  So, when making assumptions, we should assume both the postive and negative.   One thing I can tell you is that everybody that has heard my W/P 8 loves the bass coming out of those things.   Subwoofer not required. 

An amps ability to drive lower impedance loads has no relation to the amps quality. 

yes, ok.  How about, for the same db, lower impedance requires more current, which equates to a bigger power supply (ie. in A, AB) which may increase the cost of the amp.  Something like that.