As a current CMU student and startup founder, I agree with Paul's observations about the environment and the kind of people Pittsburgh attracts. I've witnessed firsthand the startup culture that is churning, and I don't doubt it will continue to grow.

However, the comparison between Silicon Valley and Pittsburgh Paul omitted has to do with the weather. Any freshman at CMU can tell you that the winter (and fall, and spring) in Pittsburgh are less than pleasant. Just last week it was snowing, in April. The fact is, for more than half the year, people won't be able to fully enjoy all those cafe's, restaurants, and cycling. The cold, rain, and snow do impact the day to day life of the people who live here and it's a factor of life that can't be overlooked. For many people, the choice between similar jobs in San Francisco and Pittsburgh is an easy one in favor of San Francisco.

Pittsburgh's startup culture is growing, and there are great companies springing up here. But as a founder, I see Pittsburgh as a jumping off point. I don't wish to live with this kind of weather any longer than I have to. Not when I have the option to setup an HQ in San Francisco. And I know the people I want working with me now and in the future feel the same way.