That is one of the many ways of doing it. I see no reason for assuming it should be the only one, or that there's something broken, to be fixed, in media creations who try to achieve humor in a different way.
"Look! That one guy can write a super-rational character, and have him fail at many things, and make it all funny! Why isn't this other randomly selected writer doing it similarly?" This is my interpretation of your line of reasoning. See what's wrong with it?
Nope. One form of humor takes more work and brings up more interesting results than the other, which is lazy, cheap, mean, and cruel. I believe the former to be superior to the latter, and thus advocate for it.
This is my first attempt at starting a casual conversation on LW where people don't have to worry about winning or losing points, and can just relax and have social fun together.
So, Big Bang Theory. That series got me wondering. It seems to be about "geeks", and not the basement-dwelling variety either; they're highly successful and accomplished professionals, each in their own field. One of them has been an astronaut, even. And yet, everything they ever accomplish amounts to absolutely nothing in terms of social recognition or even in terms of personal happiness. And the thing is, it doesn't even get better for their "normal" counterparts, who are just as miserable and petty.
Consider, then; how would being rationalists would affect the characters on this show? The writing of the show relies a lot on laughing at people rather than with them; would rationalist characters subvert that? And how would that rationalist outlook express itself given their personalities? (After all, notice how amazingly different from each other Yudkowsky, Hanson, and Alicorn are, just to name a few; they emphasize rather different things, and take different approaches to both truth-testing and problem-solving).
Note: this discussion does not need to be about rationalism. It can be a casual, normal discussion about the series. Relax and enjoy yourselves.
But the reason I brought up that series is that its characters are excellent examples of high intelligence hampered by immense irrationality. The apex of this is represented by Dr. Sheldon Cooper, who is, essentially, a complete fundamentalist over every single thing in his life; he applies this attitude to everything, right down to people's favorite flavor of pudding: Raj is "axiomatically wrong" to prefer tapioca, because the best pudding is chocolate. Period. This attitude makes him a far, far worse scientist than he thinks, as he refuses to even consider any criticism of his methods or results.