KISS deserves to be in. I'm relatively indifferent to them (I'll listen to their songs, but I don't think I own any), but it's still hard to deny they're "scary" bubblegum pop meets metal music was important to rock.
As for not performing. Meh, it's happened many times before. Sex Pistols, Black Sabbath, Madonna, Michael Jackson, Guns N' Roses, David Bowie, Paul McCartney. Both good and bad, assholes and seemingly reasonable people have all chosen not to perform.