I think a better comparison would be instead of calling your sister fat, you tell her you are upset with her. The point I was making was practicing restraint. If you go around calling people 'fat' to insult them, you are obviously very child like and I don't think the analogy helps your point.
Lol, 'my panties in a bunch'. While it feels good to express oneself, it shows maturity to not shout out 'SHIT!', if even to substitute it with 'SHOOT!', and therein lies the logic. It demonstrates a certain level of restraint, while not absolute restraint, but at least a base level of it. You may not agree. You might also be a self-righteous prick, but since you advocate lack of restraint, there you have it.
Edit: and to clarify,
"It's not a very intelligent thing to change the form of the curse words but not their content." - I never said it was intelligent, I said it made me realize how juvenile people sound when they curse non stop.
"And focus on the logic, not the implied naughtiness of my fictional example" - You are missing the point here, which I stated plainly in my first post: One could argue that speaking like a child is to have no restraint over what comes out of your mouth, not the other way around.
"You want to practice restraint? Then don't say anything instead of swearing. It's as simple as that." - Oversimplifying, a sign of immaturity, i'm concerned about you...