"I found sports at school to be painful and humiliating - mostly because I always got picked last for teams.
It felt like a punishment for being male."
This really does point to a strange logic that I cannot make sense of at all. At an all boys school, those picked first were also male - were they rewarded for being male and you punished? Having gone to a mixed school, it was more often the girls picked last, but that's by the by in the logic conversation.
When you decide what factor is influencing an outcome, you need to look at what is different between those with one outcome and the other. Picked first = male, picked last = male, everyone in-between = male. Therefore male is not a factor that is influencing the outcome.
My DH was often picked last, he was tiny for his age, that makes logical sense - do you see the difference?
I would like to see how you drew your conclusion, it points to an interesting conversation on what is happening inside the heads of people who centre their lives around gender.