They are employed every where.
They are you and I - People in general cannot differentiate between what is genuienly offensive and what may be slightly off colour.
You have a situation where anything out of line can be punished so people tend to see it as the norm.
Take the word darling, now where I was brought up its a term of endearment and was used at times to address ladies that might catch your eye. This is now termed offensive and unacceptable. I have never worked out why as I always (as a man) used it in the most flattering way and never meant any offense.
However should I use it to address a female collegue I could be up in front of HR and disciplined.
So I never use it outside the family, so I am part of the PC brigade. :-(