Music is very subjective. I know I'd get up in arms if I saw the Eagles, Fleetwood Mac, or any of their respective members get hated on.

That said, KISS has always been controversial. I wasn't allowed to listen to them as a child because my mom heard KISS stood for "Knights in Satan's Service." Still, I'd see them occasionally on magazine covers and such. When I saw them, they often had fake blood dripping from their mouths, and that freaked me out. I didn't understand why they did it - I just thought they must like blood and hurting people because they were Satanists (I was pretty young). I was both frightened and repulsed. It made the associations I had with the band very negative. Like UK TimFan says, it's illogical. I understand that the quality of their sound has nothing to do with their "look" or stage behavior. It's just such a complete turn-off to me, though, that it makes it hard for me to get past that and enjoy the music.

I'm not saying that what I feel is "right" nor do I judge those who feel differently. If you enjoy their music, more power to you! To each his/her own.