Well, I don't think it's logical to dislike someone over their opinions, but if they present their opinion as if it were facts, that is another deal.
There are people who can be very humble about things they don't like, and there are also people who act in a sort of "my opinion is facts"-way. For example, I would never be mad at a person who told me: "I haven't quite gotten into Opeth. Listened to BWP once, nothing really clicked. Might give it more spins, things could change", but if a person would tell me: "Opeth is the shittiest of the shittiest, they suck on all levels and I have no idea how people could like them", then that is another issue, and I would probably get a bit mad.