It would definitely force me to re-evaluate the school. I know you are going to the school for the education, but at the same time, this is going to require working with fellow classmates a lot. Happiness is definitely part of the equation for me in finally deciding the school I will attend and if it looks like the incoming class is going to be full of jerks, that doesn't breed many happy thoughts. At the same time, the revisit might not reflect the actual class that will attend. Many of these re-visiters could decide to go elsewhere (but if the overwhelming majority there are jerks, this probably doesn't matter). Bottom line: you will probably have to go with your gut feeling in the end.