Why do people think cussing is funny?

Well those people are the ones who cuss!  And people who do bad things are the ones who find those things enjoyable and funny. So if you're not one of these so they might annoy!  In simple words , it just shows the difference between the good and the bad :)

Well - it is sometimes - don't you think?  Depends who's cussing and the situation.  It's a bit difficult to explain.  Maybe when it's unexpected we find it funny - or when it's in a joke?

You hear a lot of cussing a lot of the time, and that's mostly habit, and like a lot of habits it's hard to break. I hate some words though, and find them offensive and would never laugh when people use them.