Apropos of some recent bloggy reading, I just feel like pointing out that blogging is a public event. Unless a blog is password-protected and open only to invited guests, anyone can read it. Unless comments are closed, anyone can comment.
So, if someone posts something controversial, they should not be surprised to get comments on it, maybe even negative ones. It's not nice to go to someone's blog and blast their opinions, of course, but if a blog post is insulting to a group of people, it might not be surprising if a comment is insulting right back.
Though I try hard not to be condescending and insulting here, sometimes I do slip. I think I have called the American public education system a "hellhole" once or twice. Or maybe that was on someone else's blog; I don't remember. That doesn't mean I dislike everyone who sends their kids to public school. I might have said some nasty things about some corporations too. I wouldn't get upset if someone found those posts and was nasty right back at me.
It's a dangerous world out here. Play nice. Or, be prepared for the consequences.