I think YC is pretty unrepresentative of the VC industry in this regard, simply because the VC industry is as racist as I say and YC is hoping to be that enterprising VC that seizes this opportunity for better returns. The YC partners have been pretty open about this - racism creates a market opportunity, and so they've put in a significant amount of working in retraining their own unconscious biases so that they don't miss the market openings that are left behind by other firms. (I should probably also say that they're not doing this just for better returns - it's also the right thing to do, but it has the side-effect of being economically rational.)

There are a few other VC firms that similarly work hard to avoid missing promising founders of minority backgrounds, but they are still the exception rather than the rule. Over time, the "rich, dumb, and prejudiced" folks will get flushed out of the market, but that's over a lot of time. Besides, they'll probably just get replaced by a different set of prejudices - nobody can be 100% unbiased, you can only hope to replace biases that are useless and arbitrary with ones that are somewhat more useful.