I understand what you mean... but I think putting out a blanket statement against these types of discussions is a huge mistake. People so often get annoyed at the people who give their opinions strongly for the sake of amusement that they fail to see the value in discussing these differences in opinion. Most opinions have aspects that were not considered, elements about which the opinion holder had never quite thought. So if I hate Shadow of the Colossus (I don't), there is absolutely nothing wrong with trying to talk to others and understand where the appeal lies; it gives me a more rounded picture of the game and, subsequently, of game design and the medium of video games as a whole.
Now of course, taking the same example and coming on here saying, "You idiots who like Shadow of the Colossus are just mindless sheep who like it 'cause it's all boring and "artsy," but it's really just a pretentious piece of crap," that would be problematic. Also one of the most disgustingly incorrect things ever said by humankind, but that's beside the point.
In short, sometimes it's annoying, but don't let the idiots cloud your vision of the value this type of discussion can hold.
