Truly, the worst kind of human beings are those who are intolerant of others' beliefs and preferences. If what someone else is doing isn't hurting anyone... Why should it matter?
Think about it--the intolerant people cause wars, commit hate crimes, and push someone to the point of suicide. In no way am I saying that bigots are the only causes of suicide or suicidal feelings. I mean, obviously they are the only ones who commit hate crimes, but causing wars? Honestly, the only wars I can think of that weren't caused by intolerance or bigotry were those over who owned what land, and even several of those were based on better-than-thou beliefs.