How do you feel about the pilot in relation to the other episodes of the series? I always felt it was a bit of a lesser episode, and that might explain why the show didn't catch on with most people.
I think it’s fantastic. Many people who watch it for the first time “might not” get it because they’re not really used to their subtle jokes. Also, since the show doesn’t use a laughing track that tells you when to laugh/what part is funny, you might miss some of the jokes (which you will probably get once you watch the episode for the 2nd time).
And regarding the reason why the show got canceled, I agree with David Cross; it was mainly because their marketing team didn’t market the show properly. That and because the show might be too smart for people. I doubt it had anything to do with the Pilot.