critical people

Why do people have to be so critical? Do people get a personal high from making other people feel bad? I notice it a lot, especially in certain classes. For a discipline that prides itself in being open-minded, etc., teachers and students are certainly critical of other's ideas in class. In classes that we are forced to discuss, there should at least be a ground rule that no one is allowed to blatantly put other people's ideas down. Maybe I'm different, but I think a classroom should be a place that people feel safe to express their ideas. If people do not feel free to express their ideas in a college setting, then there is a problem. If brainstorming and participating with ideas (especially when required to or specifically called upon), lead to criticism every single time, why on earth would someone want to participate in class discussions? Some people are more sensitive than others, and we should take other's feelings into consideration. Let's try to make the world a nicer place. Think before you speak. What is your motivation? Do you just want to make yourself look good? Is there some invisible debate team that you alone are part of? If you ever want to experience a classroom when expressing ideas and sharing them are safe and painless, come to one that I teach.