Why does all new pop music sound the same?

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....

I agree with @chayro that the horror of the Video and the book it is based upon is not generations gap or compression. As mentioned in the book, teen wants to listen to something different from what her/his older brother/sister is listening to, so there is no need to go poetic about old geezers or noncompoops. It is an intentional Manipulation, or mind-f$&k at the Industrial level, something Robert Fripp (king crimson) been bitching about for the last 20+ years.
i want to grab my crutch and hit our young poster here for not getting the simple 20min message (I do not expect anyone under 30 to actually read the book!). Then I want to hug this kid for listening to some real good music produced nowadays. I would love to add more to the list he/she provided (Orb, Flaming Lips, Marjorie Fair, Deepchord, Crippled Black Phoenix/SeDelan, Underworld, TesseracT, Therion, Lycia, Assemblage 23,... the list is long) but why bother? Bruckner under Celibidache or Tchaikovsky under Monteaux, or Mahler under Bernstein: I would also have to mention those before getting out of breath, and then I would look like an "old man". Why bother?