Ever since I started on 'em I can't stop. I don't always 100% love the match-ups, but it's fun to see cartoons fight it out with science and logic-- even if sometimes that science and logic is questionable, it's still cool to see it put into action.

While this video is mainly about one episode in particular, I feel like this video explains my (and other peoples) issues with Death Battle:

The thing is that it's hard enough to see your preferred character lose (or in the case of Grey Vs Esdeath, see the person that you hate so fucking much that you want them to die horribly win instead). But when you notice that they get the research so wrong that it could've actually ended the other way around, said hard feelings become several times worse.
However, if you watch the video shown above, you'll know that getting mad about it will change nothing, it's just wasting energy. While they are mostly aware of these issues to the point where they make fun of some of them as shown in Deadpool Vs The Mask, still doesn't get rid of said issues entirety.