As far as investors go, I doubt that they have any aversion to supporting entrepreneurs of any background. This is one industry that I would presume is more of a meritocracy than society at large. As I said on my tumblr a while back (http://bit.ly/g7jCAF) investors can see the green inside all of us :-)
There are many discussions going on about women in technology startups. The greater question is not why there aren't more founders, but why there arent more minority/female students in academia. Most of your founders are going to be a subset of those in academia anyway, so why not look at the problem closer to the source?