It makes it absolutely UNfair to only allow a certain kind of woman into women's sports. It's discrimination. We either want women's sports or we don't, we don't get to just decide some women aren't women. So if it's about total fairness, women's sports needs to accept ALL kinds of women, not just the ones deemed socially acceptable. Otherwise, by it's very nature it's NOT women's sports and it's just discimination. There is no way to spin this that makes discriminating against trans women acceptable.