It's not just imageboards either, everything has become more politically charged.
But let's not pretend that this kind of stuff comes from the right exclusively. Everyone made fun of SJW's back in the day, and the SJW's have become "the establishment" in many aspects of nerd culture. Now you can't play some Bioware RPG without getting lectured on non-binary pronouns or watch the latest Tolkien adaptation without Sub-Saharan Elves.
So some sort of pushback to that stuff is to be expected and natural.