The basic fact is that asynchrony forum posts request different social rules than live face to face conversation.
This anti-social "unless your words come from someone I respect, I don't want to talk to you" behaviour has most definitely shown to extend out into the real world. That became quite apparent during the COVID ordeal. But it is less clear if that was always the case, or if social media has made it more prevalent.
It’s far better faith to ask for some evidence than to rebuttal with “No, you’re wrong”, which is equally dumb.
If you can’t support a claim, you shouldn’t assert it as a fact.
There was nothing unwarranted or aggressive about the idea presented originally. It may not be true, but who cares? The purpose of discussion is not simply to tell truths. Nobody wants to hear that 1+1=2. That's pointless and boring. The purpose of discussion is to explore ideas and see what that uncovers.
“No, you’re wrong” is quite dumb too, yes, but a rational person would not respond with either. Instead, they would present their own take and provide something meaningful. If they really cannot find anything of value to respond with, they would not respond at all.
> If you can’t support a claim, you shouldn’t assert it as a fact.
If you can support a claim, why bother asserting it at all? You already know it to be a fact. You are not going to learn that it is an extra double fact. Once you know something to be a fact, it ends there. There is nothing more you can do with that.
When people assert something, you fundamentally know they are not quite sure about it. It is why they are still talking about it, and why they aren't just going around saying 1+1=2 all day long.