Given how few people we can afford to send into space, is it too much to ask that we send the best people we have? Leave the identity politics back on Earth.
The problem occurs when someone thinks they can determine “best” from traits that probably don’t actually matter in space, like being shorter than average or having uneven legs. I found the movie Gattaca to be a surprisingly good argument for this position despite being fiction and entertainment first and foremost.
(And I completely agree with your comment)