You should just come right out and say it, I think.
I stand by my handwaving as relevant, common experience that indicates an erosion of intellectual discourse. It should be patently obvious that I didn't have any sources for what I said specifically. There's no parenthetical or APA formatted links anywhere!
Edit: Okay, I'll go run an experiment and come back with the data. Maybe that's a compromise.
Well, you made a claim, and people asked you to prove that claim. I think it is quite reasonable to expect you to carry that burden regardless of medium. Otherwise, you should retract the original claim.
Incidentally, what you said about "people just [stating] what they are thinking" and then not backing that up with evidence is a huge problem in today's public discourse. If we don't hold those people accountable, then what we have is not a discourse, but a cacophony of random voices.
Goodhart's law is a big mechanic purging intellectual discussion.
If you're in a right leaning, 'non political' forum and you post about potential impacts of climate change, you'll almost certainly be put on blast.
If you're in a left leaning, 'non political' forum and someone posts 'climate change is going to turn Earth to Venus and we're all going to die choking' and you respond "that seems like unrealistic histrionics" you will almost certainly be put on blast.
There is verdant field of potential discussion between those two posts and it's very difficult to play there. You can, in certain sanctuaries.. but in public, 90% of the gradient causes someone to foam at the mouth if they suspect your political alignment is opposite theirs.