That is an asinine comment. Sex actually fucking exists, Jarhyn. It is real, and it has real impacts on people. Talking about sex in a context where sex actually matters isn't "sexist", it's fucking logical and rational.
All you have to do to not get this sprayed at you with firehouse force every time you join one of these threads is "these laws need to be adjusted with an expectation that people who have not been exposed to testosterone should never be expected to compete against those who have, particularly those who have been recently exposed; it creates a barrier against those not affected by testosterone from competing or participating otherwise."
That right there is a reasonable position. It protects everyone without regard to sex, or gender, instead focusing ONLY and EXACTLY on the thing that creates contention (testosterone and it's effects in competitive sports).
Egads. Fine. Only children who have managed to convince their parents, their doctors, and all logical adults that they should be allowed to irreversibly alter their bodies, including permanent medicalization and surgery on perfectly functional bodies, in ways that are nearly guaranteed to make them sterile are allowed to compete against the opposite sex.