I have an issue with people that talk "shit" (for lack of a better word) on genres of music they don't like simply because they don't like it. There is never really a reason behind saying it "sucks" except they don't find it appealing.
There is a difference between a band "sucking" or a band being something "you are not into."
A band sucks if they are sloppy musicians, if they are off pitch, if they are off beat, if the singer has a bad voice, etc. etc. A band playing music you don't enjoy but is played well does not suck. For example, I am not a fan of country music but I know that Garth Brooks doesn't suck. I don't like Tex-Mex but I know Los Tigres Del Norte are pretty amazing musicians. You may hate classical music but you can't diss on the first chair violonist, can you? Yeah, no.
I cannot stand certain bands because I don't like their lyrics or I don't like their style of playing - but I won't say they suck unless I can give a technical reason. I just say "I'm not into them." Because if it was up to me, a lot of genres would not exist, but that would make a lot of other people unhappy and people have a right to decide what they do or don't like.
So long live pop-punk! Long live industrial! Long live death metal! Long live any kind of genre that gets shit on by pretentious assholes who think they have better taste than everyone else because they drink PBRs while riding bikes to bars to sit and talk with other assholes about how great that new band that no one knows about is because no one knows about it except for them (the assholes).