Any reason you can think of. This should be easy.

They wrote a lot of the worst "songs-that-stay-in-your-head-all-day-long".

Also, Sgt Peppers.

I would say they wrote a lot of the best "songs-that-stay-in-your-head-all-day-long"

and, of course, Rocky Raccoon

They came along at exactly the right time, and they worked well together. They spoke for a generation of kids who didn't dig the previous generation's music. They were edgy enough that people liked them, but not too edgy. They wrote a whole bunch of very catchy tunes that made them quite a lot of money. They helped develop a whole new style of music.

As much as I respect what they did, I don't like to listen to them much. But I'm weird that way.

>>3
I used "worst" as in "goddamn effective", not as in "not good".

Amazing for still being as popular as they are, in spite of music-improving drugs being less popular.