A high proportion of questions posted here are homework questions that show minimal effort on the part of the OP, both in explaining/formatting the question, and in attacking the problem itself. I believe many of the regulars feel overwhelmed, and become exhasperatedexasperated (and for good reason) when the quality of a question is particularly poor.
On the other hand, I agree it's not reasonable for everyone posting here to know Latex. Would it be possible for the site to detect when a low-rep user tries to post a question with un-LatexedLaTeXed equations, and pop up a window showing basic usage?
As for aggression about errors in posted answers, I can't say I've noticed much of that... it's true that in mathematical culture people tend to be more direct about pointing out errors without sugar-coating, but also without intending any personal offense. Are you sure you aren't reading too much into the comments?