Why is Less Wrong against humor?

Err... It's not. I have seen a few comments where people have lamented the fact that their most upvoted (by far) comment ever was a light-hearted joke, rather than one with some deep insight or otherwise useful contribution.

As much respect as I have for Eliezer (which is a lot), people tend to get all emotionally attached to the "hero" of their community/movement, and suddenly it becomes not ok to joke about the authorities or otherwise hint anything negative about them at all. Doesn't go well with your whole "we're not a cult" thing.

I didn't downvote, but I don't think people were necessarily downvoting because the names mildly insulted Eliezer. I'm guessing that just didn't think they were very good names for an organisation attempting to improve the rationality of humanity. (e.g. the second one relates to AI far more than rationality.)