My parents both have quick tempers, although my mother is slightly better at governing hers. I inherited it from both sides, and when I hit puberty, it was Katy-bar-the-door on my verbosity. I was, in a word, volatile, and it took me a while to get it under control. The one thing that I didn't want to hear coming out of my mother's mouth was:
"Madam, I will thank you to moderate your tone."
I was about to get it if that popped out. She recorded some of my better tantrums, and when I was in my late teens, played them back for me. Mortified much? Oh, if there'd been a big hole in the yard, I'd have gotten in it, covered myself with dirt, and stayed there.
Tone is important. What differentiates a great writer from a mediocre one is the ability to effectively evoke tone from the written word. I think we often lose that, especially in the current overload of non-verbal communication, i.e., the Internet. The word "civility" is much bandied-about these days due to the rising tide of vitriol in political discourse, but it's something we need to carefully observe in our casual online conversations. I am, by nature and as a means of controlling my temper, quite sarcastic. It doesn't translate well into writing unless you know me personally...and has resulted in bruised feelings and punctured acquaintance from time to time.
Hopkins, for example, is quite literally-minded. I hope that he remembers me well enough to read the feeling behind the words, because I am frequently sarcastic about any number of things in my e-mail exchanges with him. I am far more circumspect in what and how I write to others, largely because very few people know me quite as well as he does. It pays to be a bit guarded. You can't really tell how people will take things in the absence of the accompanying vocal modulation and facial expressions.
Much as you can't un-say things, you can't un-write them, either. Thinking before you speak or before committing word to paper (or screen) is probably still an excellent idea. Civility also never goes out of style.