Why does all new pop music sound the same?

@simao - I understand what you’re saying, but, as a musician, I think you would agree that every era of music had what may be called, for lack of a better word, a "zenith". The Baroque had Bach, the Classical had Mozart and Beethoven, the romantic had, well, whomever, the Jazz era had Coltrane. However that does not invalidate all the other artists operating at the same time. It’s more popular opinion than anything else. The US cars of 1969-70, The 396 Chevelle and Camaro, the Shelby GT350-500, the Hemi Cuda, et al, are generally considered to be the considered the zenith of US car manufacture, although I would much rather drive my current vehicle than my 1970 Mustang Mach 1 from a comfort and convenience point of view. Indeed - all the car auctions show these cars have a higher value than anything else produced in the US, AFAIK. Onto music - I think it is generally accepted that the late 60s and early 70’s were the zenith of British/US rock/pop music. You are certainly free to disagree, but I think that Hendrix/Zep et al were the fountain from which it all flowed. IMO of course. This is not to say it was "better" than anything that came after, nor does it invalidate the contributions by any major artists. So, on one hand, I do consider the 60s-70’s era to be the "halcyon" as you put it, but so what? They’re gone, the 70 Mustang is gone. Now what do we do? I really don’t know. Admittedly though, it’s difficult to accept the substitute once you’ve experienced the original.

It is all the same garbage.
Autotune is the death of creativity. 
Long live Rock 'n' Roll.

There is great pop music out there. I recently went to see some live music by somebody I'd never heard of. My audio buddy is more geared to new stuff and it was his idea. Ariel Pink was the nights entertainment. It was great! I honestly couldn't believe the quality of songwriting, musicianship and show that was put on. Best night out to see live music in sometime. Gary Wilson and the Blindates opened. That is another story in its own. Less a mind opener than a blender, but also deliciously awesome stuff. 

I am a record producer, mixer and multi grammy winner currently still
active in the industry , although I started in the early 90's.

The biggest difference isn't really the talent, there is some great talent out there all across the musical spectrum. The reason I believe music
has hit the creative wall is technology.

Digital technology, making records for the most part entirely on a computer and distributing it via streaming and promoting over the internet has created the opposite of it's intent.

There is now SO much music out in the world it's sometimes hard to find the great stuff and due to radio formatting all the same type of music gets the heavy promotion. The heavy handedness of digital recording has given everything a similar overprocessed dynamic free sound

I'm not quite ready for a walker, and I do think there are some good new groups....Spoon, the Shins, Cage , all good stuff....I was really talking about the pop music that is constantly being regurgitated....

U2 and Beck,  great artists....  you were probably still in diapers when I saw U2 in the early 80s....