don't break the rules

I really do think people should be able to express their opinions. I have a real problem with people who would try to stifle the expression of others. Honestly though, I sometimes have to remind myself that if I believe someone is entitled to say something outrageous then I must also believe someone else is entitled to take issue with whatever they had to say. It can be hard to remember that just because I take no issue with a friend's profanity, for example, doesn't mean everyone will be as happy with it. I sometimes find myself thinking, "why are they being so judgemental?" but I always stop myself because they are entitled to dislike it. The point is, even when it is hard to remember that EVERYONE is entitled to express their opinions, I do.
Others however, seem to have an incredibly difficult time with this concept. I support healthy debate. I think it is great when people can have a constructive conversation about something that they do not necessarily agree on. I really don't even mind when debates get heated. They are more heartfelt and interesting that way.
The thing I have a problem with is when people forget the rules of the game. What do I mean by that? That you attack arguments not individuals. When you take the discussion away from what the person said and make it about who the person is, you break the rules. There is just no room for that. I have no room for that kind of behavior in my world.
I've encountered far too much of this recently and it has got to stop. I have an incredibly hard time wrapping my mind around the fact that people actually think it is acceptable to say things like, "what you need to understand is that no one will like you if you do that," or "I know in your mind these things don't exist, but..." in a classroom of future teachers! Where did they learn that this was alright? Are these people all around douche bags? Or are they simply so bad at arguing for themselves that they feel a need to attack other people?
I just don't understand. I hope these people don't act this way in their personal lives, and I really hope they learn to curb it in their professional lives. It just isn't ok. And quite frankly, I'm done putting up with it.