Definitely a lot of merit to this one! I enjoy banter so I hope I don't go the other way and just ignore someone online if they disagree with me but I've definitely seen it ignored when I try to engage with someone and go against their beliefs or ideals. I agree though that with an in-person conversation, you can call someone out for their shit and they are forced to respond to you in some way, because walking away is possible but not very common if they are a friend. We need more of that online but it's hard to have, I think.
I don't think everyone "ignores" totally, but they can discount the criticism heavily.
It is rare that good friendships end, even in the face of very difficult conditions and words.
Online is a place where people live a fantasy and start to believe it is their reality.