There's ups and downs to (almost) every addition to each and every forum, but i see nothing wrong with this. The idea that hate speech/shit talking/negative content will be up votes is literally the same as any forum post. IF someone was to post something negative / absurd enough to warrant a removal, it will be removed by the staff of the forums leaving all of the positive / neutral content to attract the up votes.
In my eyes, this is just another nifty but minuscule feature to enhance interaction on a users profile. It's a nice feature and there's zero downsides to it, it's just a way of interacting further. After all, adding ratings is a way of eliminating useless responses - so why not? \_()_/