I still don't buy that the Light x L pairing is funny for more than a moment of surprise. I don't think the video was edited to be funny... I don't know the story of the category switch, but the video wasn't initially entered to comedy.
Comedy is kind of weird because things that aren't funny in reality can be funny in fiction. In Sayonara Zetsubou Sensei stalking is funny because there is a huge chain of stalkers, and that's just absurd. I didn't find the stalking in this video funny because it's just stalking, which is creepy. (I also didn't find the violence funny because it's realistic violence.)
I admit that I could be interpreting people's reactions incorrectly, but at the gut level I FEEL I'm right and will probably continue to feel disturbed even if someone can give me a reason for humor that I find intellectually plausible.
On a totally different note: HalofBorg your Lost Episode is hilarious
