Alternative hypothesis: Your friends assume this is one of those cartoons-not-just-for-children that you talk about, and find it completely unfunny because it's a parody of something they haven't seen and don't care about.

I've been in the situation before of having a friend show me a "hilarious" parody of some computer game or whatever, and finding it completely pointless and unfunny, despite the friend loving it. And I'm pretty sure it's not because of some creationist-level bias, because I'm fine with good parodies of computer games I'm familiar with.