Well SF is clearly saturated with people working in the tech industry. As we're seeing more and more on HN, there's a huge amount of people in the tech industry

Well SF is clearly saturated with people working in the tech industry. As we're seeing more and more on HN, there's a huge amount of people in the tech industry who are in it for reasons that do not include a passion for technology, writing code or developing things. So you've a huge amount of people fairly dissatisfied with what they're doing 40+ hours a week, in an area full of similar people, and who have the disposable income and time to look for more in life outside of those 40+ hours. So it's not surprising more cultural/outdoor/etc. things are flooded with people from the tech industry in SF, I suppose, where elsewhere they would be both less people in the industry and those that are would be slightly better geographically dispersed.