I am very, very conflicted
This is an odd case, at first, I thought you were being an asshole for no reason, then I went and saw the response he left you on your review, although you did somewhat dwell on the "whatever her name is" 's voice acting, you still had a point, not only that, but it was a respectful and well written review, I would love to get more of those in fact, and yet, he ended it by saying he hopes you die, along with other swearing and insults, that's not cool at all. I think this animation is bad, but you already know that, it is the POINT you are trying to make.
And this is the problem, the people are getting mad at you because they are fans, like DeathmasterP below me, anyone who uses the word epitome properly I would expect to be intelligent, but he completely ignored your authors comments, in which you explained your disgust with the author.
But one thing to keep in mind, we can all be assholes at some times, some of my responses to reviews of my movies have been quite pissed off as well (typically to someone harassing me, but nonetheless).
Just keep in mind everyone has days where any minor thing can make them flip out, that being said, I am on your side on this one.
I cannot give this a great score because of the fact it isn't very well made or funny, but I do respect your well written considerate reviews, even if people are bastards, try not to dwell on it.