I've had similar experiences. Never posted questions myself, but I'll be Googling for help and find forum posts that are as toxic as you describe.
It's been bad enough that the Linux elitism on Lemmy leaves a bad taste, even if I haven't seen as much of the toxic parts here. I know I'm not the only person of my friends group that feels this way about Lemmy's Linux crowd.
I wager they're so used to getting away with shit that destroying evidence probably says less about the crimes committed and more about the piss-poor justice system.