The comment was trollish and inhumane, but yours was still a personal attack, and those are not allowed here, regardless of what you're responding to. Please don't do it again.
Because you made an insulting claim about the author and his or her parents. It's not your place to say such a thing, nor could it ever be justified by a mere internet comment, however obnoxious. More importantly, HN isn't a place where people are allowed to treat one another that way.
I appreciate that your intent was to defend the people the commenter disparaged, but you did it in the wrong way, by disparaging back.
