Those translations are not only unwanted but also ridiculously bad (which is part of the reason why they're unwanted, I guess). I have to translate back to the original English, as far as that's even possible, to get an idea of what the video might be about.

Who in his right mind thought this was a good idea??

I have a Firefox extension which tries to suppress the translations, but it only works for the main view, not for videos in the sidebar. It's better than nothing.