Originally Posted by Redsland
It's not the Hall of Longevity and Album Sales.
Not entirely, but that's a large portion of it. It is the hall of "fame", after all. The problem with things like the Rock Hall is that it attempts to place quantifiable metrics to something that is inherently immeasurable by those terms.
It's not just about musicianship, originality or influence--there are plenty of bands and artists who possess some or all of those criteria who will never see the inside of the Hall. Fame, notoriety and longevity also play a role. And simply because an artist's music may not be the most ground-breaking, interestign stuff on Earth does not mean that they did not contribute in other ways. What AC/DC did may have been pedestrian, but they did it exceptionally well--and their name, songs, sound, band members and logo are familiar to anyone with a whiff of an interest in hard rock.
Personally, I think artists like KISS or Eric Clapton are lacking in a number of qualities that I would assign to HoF inductees, but I also understand what they did that got them in there. Ditto a group like AC/DC.