I get what you’re saying.
Although plausible, I find it very hard to believe that these are some “good-faith participants who want to maintain their privacy” so much that they act (practically) like cowards! Especially since these posts are (usually) not some crazy rage-bait posts that everyone can recognize as such.
I really don’t know the motives either but I suspect these are bots who try to sway people’s opinions in one way or the other without letting a conversation be made.
For me it’s like entering a debate or a conversation, yelling an opinion (albeit on-topic and probably even valid), then running away.
It’s a self-destructive account, it can’t hear you.
It’s not the trickiest, but it’s not exactly easy to say it like the native speakers.