Thing is, I find it a lot easier to disregard a simple "It was great" or "I hated it" because it's just an opinion. I don't know what they're reacting to with the simple statement, so I don't wind up judging any specific element of the film when I finally see it, thus preserving my neutrality. Whereas when someone is very specific about what they didn't like, I wind up looking harder at that point to find out why they were so keen or unkeen on it, and not only is my judgement coloured but I wind up looking too hard at that point and missing something else.