As a democratic Socialist I have been convinced for years that often ludicrous political correctness is the stock- in trade- of the " pseudo-Left". Socialists have always pointed out various kinds of group oppression -and prejudice-under capitalism. But for militant socialists-like Eugene V.Debs- race, gender, and sexual orientation are secondary to generalized CLASS oppression and exploitation.
The neo_Democrats -represented by the Clintons and President Obama- abandoned New Deal " liberalism " decades ago. No wonder the " socialist " Senator Bernie Sanders of Vermont is surging in popularity.
What does it matter to the voting masses in America if they have a feminist woman president, a gay secretary of defense, and a trans-gendered secretary of state, if they all are Ayn Rand capitalists at heart ?
What would the openly gay, politically radical poet Allen Ginsberg say about gay generals in the Pentagon ? I am sure he would HOWL about it.
On both the American Left and the American Right political correctness has peaked.The Great Recession is weakening it. REALITY is weakening it.
I would say that political correctness is still a good guide for everyday manners in a truly diverse society.