Sorry. Uhm... AAAAARGH MCAT GPA GRUMBLE GRAR. I DISLIKE THINGS BECAUSE REASONS.
To a point, but more information is better than less. People develop opinions for a reason - rumors and stereotypes are often wrong, but sometimes exist for a reason. People sharing their opinion freely may place the impetus on the listener to determine what is quality information and what is inferiority-complex-bartalk, but I don't think any of it should be discouraged. Criticizing one person's opinion criticizes all similar opinions, even though many of them may have solid reasoning.
There are plenty of good and bad things about every school, including Columbia (Bard Hall? Let's be serious), and I'd rather hear everything than have people hold their opinions back for fear of criticism. The whole idea that people in school-specific discussions should be constantly projecting positive views of the school in question, and avoiding negative discussion, kindof defeats the purpose of making an informed decision.