Such as why is it acceptable for women cyclists to be openly gay but not men?
Based on a quick glance I think that in the professional women's sports world it's a lot easier to be openly gay. If so, that probably comes from a couple of aspects.
a) being a professional sports person is far less of a projected aspirational model for women. If you're already a social outlier then you're less likely to be inclined to follow those aspirational models and define your own.
b) there seems to be less myopic gender identity typing within professional women's sports and socially being a lesbian is far less equated as being weak for women as being gay for men.
c) there's a lot less money in professional women's sports. Therefore openly expressing your sexuality is far less expected to affect the contracts that may be on offer to you or the sponsorship you can attract.
Mind you, I'm no expert on this and I could just be talking utter horseshit.