I actually meant to make a comment on this awhile back but forgot to get back to it. So here goes:
I agree that they are not the best at some specific genres in rock, including psychedelia, hard rock, blues, etc...
However... I think that they ARE the best at one form of rock: Pop (some call it Top 40...). They are the best Pop band of all time, and probably specifically because of what you mentioned: that they could incorporate any sound form into a workable pop tune. I also think their incredible voices, song-writing, cohesion, rhythm, prolific body of work, experimentation, etc... makes them the best.
But just at POP. Not the blues, psychedelia, hard rock, or any related genre. Just pop.
Well...
That's just a low blow!
On a serious note: starting from Help! and Rubber Soul, their music became nuanced or layered enough to... not be any more of those "Love Me Do" level pop tunes. At least it was serious enough to hold my interest...