If you think I'm being too general, that's your opinion, and you are entitled to it. I'm attacking a mindset, more than a group of people. I use the term leftist because it is shorthand, and I figure most people understand what I mean when I use it. I can use the term post-modernist, if that is more suited to your sensibilities.
The driving force behind post-modernism is the belief in Jacques Derrida's deconstructionist philosophy. And moreover on the idea that western civilization is based on phallogocentrism, ie "the patriarchy". The end game is to basically undo everything that has been achieved by western civilization, and recreate civilization based on relativistic morality, to put it all in a very small nutshell. Marxist communism (marxism for short), if you'd like me to be specific, uses the deconstructionist philosophy basically to confuse people who don't know better, and marxism is used by some people to whip the misguided post-modernists (who may not be aware of the end game or even the roots of their world view) into a frenzy in order to sieze control in the turmoil.
I, for one, kinda like western civilization, and don't believe that Derrida's criticisms of it are at all legitimate. I also understand that marxism, and pretty much every other form of communism, has always historically caused massive death, destruction and the elimination of personal liberty. I like personal liberty, and am not a big fan of state sanctioned mass murder, as such, I see it as the least I can do to criticize the result of deconstructionist philosophy wherever it crops up. Speaking the truth is the only way to combat it and bring good into being.