It's a frightening experience to be confronted by someone in a cursing rage, because you never know when that person will cross over the line from verbal to physical abuse. Whoa . . . It's a big step you're taking to call people that swear morally deficient. I think your point about verbal abuse turning to physical abuse may be valid, but you have to keep in mind that not all swearing is verbal abuse and vice versa. It's perfectly possible to degrade and abuse others using words you can say on television.
Language can be violent and inflammatory without swearing.
Even if you're by yourself and you hit your thumb with a hammer, when you swear, you are more likely to throw the hammer than if you don't swear. I also don't think unlimited self-control is the virtue you make it out to be. Honestly, I think swearing is a sign of immaturity. That said, I have admitted that I am immature, because even I mess up sometimes. But I hope that as I grow older, my level of maturity will grow and I will slip up less and less.