I can honestly say now that I nixed a guy because of his taste in music.
If your pick up is "Just wanted to say hi!" then I will take a look at you. Really, I will. Because the ball is in my court and it's more honest than anything else I've posted here.
But when the only interests you show are your tastes in music, and your top band is Nickleback, I for the life of me cannot take you seriously. Because Nickleback is just... blegh. Seriously, the most cliche about liking Nickleback is admitting you like Nickleback. Nickleback isn't one of the bands you advertise that you like. It's not the awesome cousin you drag everywhere because they're awesome. Nickleback is that cousin that you pray to the heavens above to stay home whenever you go somewhere, but doesn't because they want to show off their "awesome new weave" when in reality it looks like it was swept off the floor of a drag queen's reject pile.
No, Nickleback is a dealbreaker. No ifs, ands, or buts.
