You mean a cake brokerage or something?

These platforms connect service providers and consumers. That should be obvious, I think.

A better challenge would be if these same platforms allowed racial selections. Which I think everyone would be uncomfortable with in a way “let women avoid men” does not evoke.

Probably because of motivation. To my knowledge, there’s no evidence of racially motivated bad behavior on these platforms, but there certainly is for gender-based bad behavior[1]

So the apparently-similar hyptothetixal is not that similar, though still useful for rhetoric.

1. https://uber.app.box.com/s/lea3xzb70bp2wxe3k3dgk2ghcyr687x3?... (Page 20)