Why do people hate Nickelback so much?

Someone asked a question on y!a today, listing a bunch of rock groups and asking which one was the favorite. The rock groups they listed were Iron Maiden, Metallica, Black Sabbath, Megadeth, and Nickelback. I chose Nickelback as my favorite. I'm not a big fan of theirs, but I prefer them over the hard stuff. Hard rock kind of hurts my head and my ears. And I got 8 dislikes for saying Nickelback was my favorite, far more dislikes than anyone else who answered. I don't think that's fair because I should be able to have my own opinion, right. I mean, is it my fault that I don't like heavy metal and would rather listen to Nickelback?