James Cameron: Knife Robots And Anime

Avatar 2 is around the corner and so we return, boomerang-like, to the question that has dogged mankind's footsteps since Jim Cameron first cursed us with the image of a robot wielding a little knife in 2009. Why?
As it turns out, it's animes fault. Or animation at least.
Special thanks to the fine folks over at OCRemix for the amazing music and the community at /r/Gundam for helping me find the most ridiculous mecha possible to talk about.