I dislike Nickleback because I think their music is shit. Other people love them because they think their music is the shit. Its a matter of opinion. Your opinion is different from that of most of the people here, judging by the comments I've seen about them (everywhere but on this thread of course due to the OP Effect*), but its just as valid as anyone else's opinion.
*No matter what the topic, the majority (or at least a large minority in cases where the OP's view is incredibly unpopular) of responses will be in agreement with the OP. I'm not sure why, but its something I've noticed