Are you saying no criticism should be levied whatsoever? That if you don't think a student athlete is living up to their potential, you should just not say anything at all (the "if you don't have something nice to say, don't say anything" mantra)? If so, I very strongly disagree with you. Criticism is a part of life, and when I say criticism, I mean someone disagreeing with the way you're doing things or thinking that you could be better. You get criticism from your superiors, your peers, and sometimes even your subordinates. Criticism is there to make you better. Nobody is perfect and everyone could improve something - if you are able to learn about a weakness of yours in some way, it might not necessarily matter where it comes from. Sheltering people from constructive criticism can be downright damaging.

On the other hand, are you saying that people shouldn't be calling names? That those saying Nick is an idiot, or a jerk, or whatever other insults, are out of line? Are you saying that criticism, if not delivered appropriately, can be damaging? If so, I would agree with you on that.

The problem with your metaphor is that if the server screws something up or the window washer doesn't wash your windows to your liking, there are more options than just the two you stated: "yell at them" or "do nothing about it." There's a polite and constructive way to express dissatisfaction with the product you are paying for, and you as the customer have the right to express this. This is a problem I've felt about CB for a while - too many people here think the only options are to be a huge jerk when you're not satisfied, or to sit and say nothing about it and just accept it, with only the latter being morally acceptable.