All this "calm down" complaining is bothering me. I'm sorry it annoys you, but it doesn't bother me a bit, and sometimes helps.
Sometimes I would have a problem with a a kid in the library, thought I handled it well, then would try to tell my supervisor about it and talk really fast and babble. She would tell me to calm down, it's OK, and I would take a couple of deep breaths and tell her the story calmly, succinctly, clearly.
Sometimes when things are really going badly and I call Customer Support, the same thing happens - I speak quickly and lose my train of thought. Only the agent just tells me she/he is there to help, but please calm down to explain my problem. Bless them. It's never failed, and I applaud the patience!
The only time it really bothers my is if I am crying uncontrollably (very rarely). I can't calm down then until I get the pain out. I just try to avoid people, then, but sometimes can't.
If it bothers so many people, why do so many other people use it and expect positive results? It must not annoy the calmer person, because he is using it on someone else.