Lotsa real smart folks can turn the air blue at a moment's notice. Has nothing to do with their education at all.

If the concern is how much words hurt others, any words carefully chosen can do that, whether or not they involve crude language. Silence itself can hurt others.

I don't see anybody endorsing sexism or racism and so language suggesting either or both would by default be unacceptable, but then again entire school districts have become unhinged over Twain's HUCKLEBERRY FINN. Most complex stuff is real complex.

A distinction should be made, IMO, between strong language aimed at others ("You MF!") versus frustration aimed at inanimate objects ("The goddam bus broke down and we were late for the movies").

What is profane for the preacher might be acceptable vocab for the public. I'm not seeing Jack Nicholson's films dubbed with "Son of a gun" and "Doggone it" any time soon and if they were I wouldn't shell out a penny to see them.

Kids realize from an extremely early age which words and phrases should be repeated at the supper table and which words and phrases should not be. Among themselves, they generally speak freely, and properly so.