I agree with you. People need to learn when their opinions aren't welcome. I know how it feels when people correct you and make you feel like a loser, it pisses me off too. They just do it to make you look stupid. And they don't realise that criticism hurts. I remember the first time I posted a story on this site and got rated down with a nasty comment about how I write. I was so pissed off I deleted it and then regretted it because I also posted it on another site and everyone was saying that they liked it.
It's because of the bitches on the MCR section that I stopped writing for them, which pains me because I had tones more ideas for those fics.
And I agree with the self inserts thing, if people don't like it then why read it? It's only going to piss them off. And then pisses off the writer for having a bitchy comment about them