If you get mad and start cussing during a competition you loose. Plain and simple. Any drop in focus and that's it. IF you get mad you start to tense up and that is it, you can't catch that puck, strike that drive, clear the bar. you see it all the time in youth competitions.
Friendly banter is trying to get the guy you are competing against to loose his cool while you keep yours, cussing is horrible for this (and also while avoiding any technical fouls.). Don't know why but cursing at someone gets you mad, often madder than the other guy.
Athletes train hard not to get mad but to live in the second and just shrug it off. When you see someone rage you don't see them competing anymore for a while. They need to cool off and refocus.
The myth that "regular" sportsmen are just as bad as gamers is a nothing but a myth used to excuse the horrible behaviour of gamers.
On a lighter note athletes and gamers have more or less the same diets. Though athlets, atleast in the world of T&R do drink more than gamers.
I agree with most of what you said, but what I don't understand is why you then think that enforcing good behaviour is necessary. Censorship isn't going to prevent displays of anger, but it is going to frustrate people who happen to use censored words in regular conversations. I curse all the time, but I learned years ago to control anger and emotion during competition. I still curse. It's just a byproduct of my upbringing and environment. Cursing doesn't "get you mad", as you put it. Words are words, and there's nothing inherently different about one that would make its user feel differently than using another. You choose words based on your emotional state, but your emotional state is not in turn influenced by your choice of words. It's a one-way street. I curse all the time, talking to friends, talking to strangers, talking online and talking in my daily life. I understand that some people don't like listening to that kind of thing, and for those people I adapt. But I don't want to be forced to do this at all times, because with some people I'd much rather interact in a way that's most comfortable to me.
I'll give you an example. I'm part of a chat group on Twitch that I hang out in when I'm watching Twitch streams. It has a word filter because of some config screwup, and it's the most infuriating thing in the world. I'm not the only one who feels that way either. These are people I'm comfortable talking with, and I know they're not offended by my conversational habits. But the conversation is limited by the system's filter, and that's extremely annoying. Am I being harmful by using words that some may find offensive around a group of people who aren't offended by them at all?
I played baseball competitively for over 15 years. I played in high school leagues and university leagues, with players who would go on to play professionally and with players who were good for amateurs but never good enough to make it pro. Cursing was just how you spoke. There were angry players and relaxed players, but everyone cursed, because it was just what you did. You hit the shit out of that ball, you fucked up your arm, you pissed on it, you and your buddies were bitches and pussies and fuck-ups and shitheads and everything in between. That was the culture I grew up in, and while I understand that some may be more sensitive than me, I would've been furious if I was forced to change how I spoke around others who spoke the same way. There is nothing inherently wrong with cursing; it's just words.
Now, once you get to publicly-viewed levels of competition things change a bit. I had teammates who were good enough to play baseball professionally but were looked over because of their temperaments. The same is true in competitive gaming. Once sponsors are involved, a player who is unable to control his speech in public is going to have less success that a player who knows how to act professionally with a sponsor's name attached to his. In that way, the system works entirely as expected.
Now this is all a very round-about way of addressing the problem of mandated censorship. Your argument, as I read it, boils down to "cursing makes you made, and competitive players shouldn't be mad because it negatively impacts play, so removing cursing from in-game communications makes sense". If I'm incorrect in that assessment then please correct me, because perhaps I'm just misinterpreting what you say. But I disagree with this stance because I think the notion that cursing causes anger is absurd, and because I think that censoring speech without letting users opt in or out of the censorship will do nothing to reduce the amount of flaming and trash talking in games. Instead, it will simply frustrate the segment of the playerbase that isn't offending by cursing while placating the segment that finds it offensive. At that point, why not just give people the choice?