I thought his comment was insightful, too, until I read the last line. Then it just sounded like arrogance. I suppose I read a positive spin on that comment--something like "well, most people just haven't discovered the facts about how great LISP really is," but the round/flat earth analogy doesn't necessarily foster such a reading.
I can see it that way now that you mention it, but when I read it initially, I gave it a more charitable reading.
It's possible that Mr. Costanza means by "not arrogant" that it isn't a reason to think that you're better than the flat earther at all. There are plenty of people for whom knowledge of the curvature of the earth does not often come into play. It isn't out of the question that Mr. Costanza means that those folks could learn about the shape of the earth if it came up, and that the fact that it hasn't come up for them is a matter of circumstance rather than in-born ability.
