I agree. On the one hand we are encouraged to be cruder and more offensive all the time because that "pushes the envelope" and somehow constant envelope pushing is a good thing (Is there an "envelope" anywhere that has not been "pushed" to the breaking point?). On the other hand, we are supposed to be extremely sensitive and it is considered the hightes virtue to be constantly offended at everyone and everything. Imagined slights become real and real insults become thought crimes, only it is also a thought crime to not be offending or offended. This chaos accomplishes two things:
1. A general breakdown in civilized norms creates opportunities for degenerates, demagogues and criminals.
2. Someone has to enforce the double-standards and this is an opportunity for the high priests of political correctness to dictate how people will be "offended" or not. It is like something out of "1984."
And that, IMHO, can be taced back to the do-you-own-thing mentality that started in the 1960's and snowballed since then. Back in the 1950s (and before), people dressed -- hats, gloves, etc. -- just to go to shopping. Boy, have things changed.
As my mother (RIP) drummed in my head: "Manners are free. Get the best you can."