The sad reality is that the vast majority of people out there want total control over who is in their vicinity.
While i can completely respect this in live situations, in online forums if you're indifferent to someone you can easily ignore them (unless, of course, those individuals are intentionally addressing you).
For the most part however I think those with hardened mindsets need to expose themselves to different cognitive perspectives from all sorts of different people from all walks of life and in an online & anonymous environment this can be safely done because you won't gather any moss.
The day that MySpace introduced 'Groups' was the start of Myspace's fall...everyone started pouring into 'like-minded' areas totally avoiding the municipal forums.
The only example I can give is being in a forum where 70 percent of the posters are Trump voters, realize this, match up and then lock themselves away from the remaining thirty percent because they don't want to overhear anything challenging.
I used to think that 'Herds' were just a High-school thing but it's actually the start of a permanent trait harbored by most humans right up until death.
And even as death approaches and people begin asking 'who', 'when', 'where' and 'why' you'll notice, once again, they go seeking the largest herd.