I see this time and time again: Instead of engaging with dissenters, forums, groups of all kinds just evict people who are perfectly willing to talk. In principle, that's also acting to "simply eliminate people they find disagreeable."Er...I was asking what you do about people who are willing or even enthusiastic about killing others, and I think this is qualitatively different from exclusionary behavior. 'Eliminationist' may not be the most semantically optimal term but it's the prevailing one to describe ideologies that accommodate or promote things like mass murder or genocide.
Certainly someone who reaches the level of Anders Breivik's extremism is beyond talking to. However, it's the height of arrogance and immorality to treat people who are perfectly willing to talk as if they are him. What I see so much of is the treatment of sincere questions as if they are such extremism.
But lots of people with eliminationist ideologies are perfectly willing to talk, because they wish to recruit and promote their ideological viewpoint. Perhaps you could furnish examples of what sort of sincere questions you see 'being treated as if they are such extremism'.
What I see most of, is people not gathering data, not communicating, and eliminating first, asking questions never.
It's also possible that this is a function of your perspective and you're simply not looking in the right places. I can't help feeling that you're avoiding answering the question by simply restating your opinion over and over - 'outrage mongering' 'information buble' 'groupthink' etc.
I get that you think this is a big problem, but while you acknowledge the existence of extremists who put their ideology into violent action, it sounds like you just don't know what to do about those people so you just omit them from your model of productive discourse and are then surprised when people critique your model.