discuss what makes current sports unappealing to rationalists

(1) Like CronoDAS, I dispute your assumption that current sports are unappealing to rationalists. To the list of counterexamples already furnished, I add American football (with its astoundingly sophisticated strategizing) and baseball (with its well-developed culture of betting and probability calculations).

(2) Yet it does seem to me that aspiring rationalists are less interested in athletic sports than your average person. But even if this is true (and even if it remains true after controlling for education and income), it doesn't entail that the fault lie in sports. A more plausible explanation is that rationalists turn up their nose toward sports because of the kind of people who shout about sports at bars. In other words, aspiring rationalists actually just dislike sports enthusiasts, and the sports themselves get the hate spattered on them by association.