It makes interesting food for thought (leaving aside, perhaps, the fact that the Rolling Stone 500 is entirely subjective). The author writes:
By the end of the 70’s, The Beatles, Led Zeppelin, Black Sabbath, the Motown greats, and other genre innovators quickly extracted the best their respective genres** had to offer, leaving little supply for future musicians. The counterargument to all of this, of course, is that the RS 500 skews unfairly towards the earliest, most groundbreaking works of music and unfairly penalizes later creations for simply coming after other works. For example, why was Green Day shut out of the list?
Read more here.