I agree that making policy decisions based on racism and sexism, especially when the affected population has no alternative but to be subject to those decisions (say, no other place to look for work, no other police force to seek protection from, etc.), is wrong. That said, I find it just as wrong to brand other people as bad or evil because they've got some silly view.
To put it quite crudely: The primary job of YC is not the policing of ideas and thoughts of people posting on HN beyond keeping things relatively civil.