How is it "dangerous"? I'm expressing my personal opinion on a relatively obscure site on the internet. It is one of the least dangerous activities I can imagine.
Edit in reply to rosser: I agree with you there.
Even if they're the nicest person you've ever met.
Care to back up that assertion?
"Unnecessary" and "dangerous" are quite different.
See, he's not holding himself to your standard of evidence. That would require mass mindreading, plus the ability to irrevocably demonstrate the authenticity of such.
Rather, he's backing up that statement with evidence in the reader's head, counting on most readers to reflect back on their life experience and see if his statement fits. He has faith that it will. In my case, it does: I agree. I'll even upvote him.