I guess we will have to agree to disagree. Perhaps you are unfamiliar with their work post 1965.
The group is probably guilty of that in the early years, early 60's. Even then, while the music was pop bubble-gum, the technology behind it was ground breaking (not to mention the marketing and media manipulation). Rubber Soul is considered to be one of the most ground breaking albums ever released. Songs like "In My Life", "Norwegian Wood", Michelle and Nowhere Man are timeless. If you understand the background that went into their art (especially compared to what was going on at the time) you'd be amazed.
By the time you get into Sgt. Pepper, White Album, Yellow Submarine, Abby Road and Let it Be they were a full on pop/political juggernaut like we've never seen. They were fantastic writers, performers, artists, arrangers, editors, directors and producers for performances that spanned pop, classical, jazz, blues, ballads...they did it all. Nobody compares.