The Beatles are arguably the best band of all time.
Early Beatles defines modern pop structure.
Late Beatles exemplifies the breaking of these structures, while still holding on to some of them.
Both are overrated in the older crowd (mainly because of their disconnect to what music has accomplished since), and underrated in the younger crowd (mainly because of their disconnect to older music, partly due to perpetual attention paid to a saturated market)... because culture.
Led Zeppelin are arguably the best band of all time. Most of their early discography (1-6) can be played in most places with most people enjoying it.
Radiohead are arguably the best band of all time. Cryptic introspections of reality, mixed with emotionally charged tonality and rhythm.

Regarding most of the other comments:
Capitalism craves formulas competing for the common denominator of an ever growing market. It's natural for the common denominator to be vapid (most of the time) to those looking beyond the surface.