I know that there are VERY FEW female YC founders and I know that having male coders looking at my application is going to totally work against me, if for no other reason than they don't relate to me.
Individuals tend to internalize negatives. If you tell them that they aren't going to relate to you because they're men, they're going to internalize that and have trouble relating to you.
There is plenty of overt and veiled sexism in technology -- much of it, you can't control. However, if you come into every scenario projecting an assumption of sexism, that's likely what you'll always find.