It was 50 years ago today....

Back when Rubber Soul and Revolver came out it was far more important culturally than simply a new pop album. In the context of that era there was absolutely nobody as hip and interesting as these guys in the popular music world, and you'd sit in front of the stereo (or mono) and be blown away by the whole thing...just musically miles ahead of everybody else on every level. At 15 I was headed home from some shopping mall in Hawaii in my mother's car when the new release of "I'm Looking Through You" came on the little Toyota Corona's radio before I left the parking lot...I sat there stunned for the entire song. That didn't happen with me often, maybe another time with Aretha's "Respect"...still...maybe you had to be there, but whew...

That rooftop concert, believe it or not, I was standing in the street below. I just happened to be walking by, my Dad had is office about 300 yards away.

wolf-garcia, that's how I felt when I heard Traffic.

Harold,

I doubt  a single one of the musicians you mentioned respectfully would agree that prog rock would have happened without the Beatles.  Anyway, the fact is that it didn't.  Revolver was released in summer of '66, featuring tracks with classical instruments, Indian instruments and the  track Tomorrow Never Knows, which pushed the envelope quite a bit. Strawberry Fields Forever was produced in late '66 and released in early '67, still ahead of the wave of forward-looking (or -sounding) Brit bands you mention (mind you, I also like those bands and "was there, so to speak"). 
One of the valuable (to me, at least) things I learned in school came from a music theory teacher.  I don't remember if we were discussing fugues or twelve-tone music or what, but he told me "it doesn't matter how complicated or sophisticated the method of composition is--what matters is 'is it good?'"  I don't think the Beatles were interested in creating genres or producing music for art snobs--just music that "is good."  Since we'll never know what would have happened without them speculation is pointless.