Just because you could make the same argument for any group, does not invalidate the argument. It speaks to it's universality. If getting them funding were the problem, it would call for a different fix.
The problem is getting them to apply, to make them aware the option even exists, and to get them to think like entrepreneurs to prepare them for the rest of a YC like process. We just come in earlier in the life cycle and are using a succesful business practice as a tool for social good. We got 5 new incubees over night, so they do exist, and we are rolling.
It'd be interesting if you could backup your intentions with some numbers. I think you'll find the startup community, specially in San Francisco and the Bay Area, is specially open to all cultures and sexual orientations.
In any case, the best of lucks! :)