he was talking about post modern intersectional feminism
No, he wasn't. In fact, he didn't even mention how being post-modernist could cause real-world harm. He mentioned that, as an argumentative tool, it could be used to attempt to deny what we have come to accept as objective truths. Certainly, that has the potential for harm. That DOES NOT MEAN that post-modernism in and of itself is harmful. Besides, you haven't even shown that Sarkeesian is post-modernist, you just presented it as a given.
Your argument here is "Guns kills people and she owns a gun so she kills people" (without actually even showing that she owns a gun, incidentally). You're two steps removed from an actual point.
the feminism anita practices causes real world harm because it deny's biology and science at a visceral level, it's also mostly bourgouise petty gripes that have the effect in the third world of crushing real change by in practice taking up too much oxygen substituting pressing and dire gripes for weak and imaginary ones.
Has Sarkeesian denied biology and science? Can you show me how she has? Also, how does denying biology cause harm?
Your second argument is concern trolling garbage, though. "You're a bad person for discussing X because Y is a bigger problem" is thought police bullshit. People are allowed to discuss whatever they want to discuss for whatever reason they want to discuss it. What, you think YOU'RE the arbiter of what constitutes "imaginary problems"? Who are YOU to decide that how women are treated isn't a real issue and isn't worth discussing? How do YOU know that she's taking attention away from what you consider "real" suffering? If attention is a limited resource and we are responsible for using it to solve real-world problems, then aren't you an even shittier person than Sarkeesian spending this time talking about a pop critic who offends you instead of going out there and changing the world for the better? "Imaginary problems", indeed.
AMAZINGLY, after all this time you have yet to mention a single one of Sarkeesian's beliefs, let alone how it causes supposed harm. Keep working that "labels = arguments" angle, though, I'm sure it'll work out in the end.