Well, for one Metallica was eligible this year but got voted down.
For another, with a couple exceptions, the inductees that got voted in have little, if anything to do with Rock and Roll.
Here's the list:
Dave Clark Five
Now, I like John "Don't Call Me Cougar" Mellencamp, but are we really to believe he had more of an impact on Rock and Roll than Metallica? And what the fuck is Donna Summer doing on this list?