Ok, maybe offended is too strong, but he does have a problem with this scene - as he quotes it:

Maggie Simpson gets an IQ test. Oh the hilarity: Simon Crowell is the admissions director! She scores high. “Meet Maggie Simpson,” he says to another school official. “IQ, 167.”

“One sixty seven!” says the other official. “That’s amazing for a Christian!”

I missed the episode, but I don't think this is a "gratuitous" shot at Christians as Lileks thinks. Based on the transcript provided, my first thought was that this was a shot at the "intellectual elite" who would actually be surprised by a Christian with a high I.Q. It's making fun of those people, not of Christians, I think. Seems clear it's pointing out the idiocy of the prejudice. My advice, don't be so quick to be the victim.