Reason? It's a popular internet fighting ground for years now. Feminism vs MRA both united vs common sense. There isn't really much more to add to it.
But reality is that most people on forums are from most privileged position in world. Not within there respective places of habitation mind you. If they were fighting tooth and nail for their better status in the world (like I have basically given up on that. Working two jobs with this being my one of my vents not to give in to substance abuse) they wouldn't have the time for this. I meant privileged in terms of the whole world. Western countries have homeless people that live better than hard working classes of second, not to mention third world.
We all need ideals to live by (and to crap on, we are only humans) and not having real bogyman we often invent one. We see something that we understand is not right and we construct narrative around it, start seeing every thing from the perspective of that narrative until our perception of reality becomes seriously skewed. And that's basically it. Both sides do that while us "common sensers" (yes I do put myself there) do the same just in different fields. We just don't construct narrative around gender politics but around different stuff (mine is world politics). You can't really prevent that but if you understand that you can somewhat lessen the impact. Not completely eliminate it, not even close. Just prevent outing your worst thoughts into the world.