It's another case of positive rights conflicting with negative rights.
Title IX is fundamentally a negative right: it restricts institutions from discriminating on the basis of sex. The fact that compliance requires funding makes it look like a positive right, but the spending is really an enforcement consequence, not the right itself. Women’s sports exist because institutions were prohibited from allowing male participation to erase female categories. That was the defined negative right. Redefining sex to include male bodies removes that negative right, essentially removing the protected category and nullifying the original purpose of Title IX. The trans group is demanding a new positive right where the original law never created, and that positive right necessarily destroys the rights of biological women, essentially doing the very thing Title IX was designed to prevent. The erasure of a space for biological women only.
My parents, my faith, and my society, they all taught me to respect others, maybe I don't understand the animosity because nobody told me there was an "unless they are too different" exception to the respect rule.
This isn't really a kindness issue, though. It's a compromise issue. If a framework can't be established where the only framework is a binary choice that exists to either have animosity toward biological women or animosity toward trans women, then the framework itself is "unkind."
It’s really a tradeoff problem. When two groups have mutually exclusive needs, pretending there’s only a binary choice for a solution leaves no room for respect.