[...] given human nature, if people got hit on the head by a baseball bat every week, pretty soon they would invent reasons why getting hit on the head with a baseball bat was a good thing.
And then it dawned on me. Roughly half of human kind, women, are inflicted with a painful experience about once a month for a large period of their lives.
So, if the hypothesis was correct, we would expect to have deep-sounding memes about why this was a good thing floating around. Not one to disappoint, the internet has indeed produced at least two such lists, linked here for your reading pleasure. However, neither of these lists claim that the benefits outweigh the costs, nor do they make any deep-sounding arguments about why this is in fact a good thing overall. Whether or not they are supported by the evidence, the benefits mentioned are relatively practical. What's more, you don't hear these going around a lot (as far as I know, which, admittedly, is not very far).
So why aren't these memes philosophised about? Perhaps the ick factor? Maybe the fact that having the other half of the population going around and having perfectly normal lives without any obvious drawbacks acts as a sanity test?
In any case, since this is a counter-argument that may eventually get raised, and since I didn't want to suppress it in favour of a soldier fighting on our side, I thought I'd type this up and feed it to the LessWrong hivemind for better or worse.