I assume you're referring to starting their own startups or joining one correct? While I agree there likely is some confirmation bias, I can at least say that

I assume you're referring to starting their own startups or joining one correct? While I agree there likely is some confirmation bias, I can at least say that I included those who joined startups. The sad part is, there are very few of them. When I was thinking of starting a startup at CMU, I was completely blown away by how little people there cared about taking risks. In 2010, the only startups people knew about were really Palantir and Facebook. In 2012, people at CMU actually still buy the tagline that Facebook is a startup. It would be great if someone could change this, but as of right now, I'm relatively certain there is less confirmation bias than you think.