This is a ridiculous witchhunt, 8chan is a platform for many different boards with different opinions, the media framing it as a right-wing white supremacist forum makes wonder if its ignorance or malice, /leftypol/ is probably as big as the /pol/ boogeyman, and thats just politics which is just a part of the rest of the boards. No one is asking to close Facebook because Tarrant uploaded his shooting video there, why…
Facebook, as you know, moved extremely aggressively to remove the NZ shooting video, along with other extremist content. Basically Facebook employs a raft of people to prevent the thing that 8chan was trying to encourage.