Because the enemy is there.
Because that is where the fight is.
Because you can't fight the culture wars in an echo chamber.
I haven't heard of the great battles being fought on Twitter, etc. All I hear is how they unjustly continue to throw people off that they disagree with. I disagree strongly with their illegal unconstitutional acts - and they haven't done anything to me. So far, they can't reach me, which suits me fine.