You raise a good point. It's my personal opinion, however, that with the coming of the Beatles, it pretty much told the record companies that if they want to make millions, then follow the formula... The Beatle's arrival, to me, was just the "writing on the wall", so to speak.
I hear you, and you've got a point, too. But consider that much of the Beatles' early pap was a product of Brian Epstein's successful attempt to clean the band up and market it to a broader audience. Before Epstein came along, there were no Edwardian suits . . . no Love Me Dos. The Beatles were a leather-wearing, falling off the stage drunk rock-and-roll band. Lennon even once wore a toilet seat around his neck on stage.
Once the Beatles made a conscious effort to be artists rather than entertainers, they shucked most of the schlock.