Examples are abundant and easy to find. Here is an example of sexism and discrimination coming from Paul Graham. Highly relevant to this discussion about female founders at YC.
http://www.thewire.com/technology/2013/12/paul-graham-revive...
Women are getting harassed and discriminated against in Silicon Valley tech companies all the time. Take this example from Github: http://www.theverge.com/2014/3/19/5526574/github-sexism-scan...
This needs to stop. And comments like yours are just one more example of how deeply rooted sexism is on this site.