Don't get me wrong, I do enjoy rock music (among others), but assholes like Nickelback are making terrible example of it. When someone asks me what I listen to and I reply "rock music" the person often reply along the lines of "ah, ok, like Nickelback?" And that's just disgusting.
I don't actively hate on them posting shit on the internet on my own or marching with antiNickelback sign in RL, but when someone asks or when discussion revolves around, I tell him I hate the band.
Being successful musician has nothing to do with it. People like Kanye or Taylor Swift made way more money with their (IMO shitty) music, but I don't hate them as Nickelback. Because they (probably, or at least not that obviously) don't ruin the genre they perform in.
Edit: Half of what I want to say is probably lost in translation as English is not my native language, so I can't make all the nuances I would do in my language.