Usually if the post is as bad as you seem to be describing, I will kind of poke fun at it and post a little remark about it. Although it seems like you're really exagerating on how bad they are. Maybe you should search google for the English Majors forum, if grammar is in fact that important to you. We're not being graded on our posts, and most all of the time you get what the person is saying. Even if they have a wall of text which includes not ONE period at all, at the end you've made out what their point was.