I never thought of the left as puritanical. They may pretend to be, but I've always seen them as hypocritical, hedonistic wasters like Barbara Streisand.
There was a book out recently, "Do as I say, not as I do", that exposes the lifestyle of these creeps. According to the author, even Ralph Nader is a fraud, living in luxurious homes in his children's name.
That's what I think that "PC" is; an expression of intolerance to any deviation from dogma. The thought control of Orwell comes to mind. I have always considered being conservative as having minimum standards of behavior, like a building code, rather than any particular fashion of behavior. OTOH, the left are into fashion and lifestyle, as you mention, and not standards, which explains their hypocrisy. They are compelled to need a government that provides a "libertine" society for their psychopathologies. As do Striesand and Nader.