As has already been explained, it is up to the Mod of each forum how much profanity they will allow in their forum. Some forums allow more than others. Since we like to keep the HTFs as friendly and family oriented as possible, there are much tighter controls for them.
In the VA forum we run a pretty tight ship, but we do allow slips sometimes. It usually depends on the word, and the context it's being used in.
Where I grew up, almost everyone uses the more colorful words in their discussions. Social status really doesn't have anything to do with it. But what is acceptable there, may not be as acceptable in other places. Since moving to VA, I've cut way back on the language I use in normal conversation. Why? Because it isn't proper thing for the area I live in. Do I slip from time to time? Of course I do.
If some really feel the need to use that kind of language, then just do it someplace else. Since it has been made clear what is acceptable here, please follow the rules.