Interesting. For me as a complete outsider (Italy here) California and the Bay Area specifically is seen as THE place for IT startups. Is that not the case? Or maybe was it just like that in the past but not anymore?
The truth of the matter is the Bay Area is a great place for tech companies because of the sheer volume of engineers. The reason so many engineers live in the Bay Area (and a handful of other cities) is (and I say this from experience) it's terrifying being an engineer in a city with only one or two tech companies.
I moved from SF to a smallish city in my late 20's, and I was only able to find one tech job to apply to, and it wasn't even for a technology I already knew. I was offered the position, and spent the next 6 years treading water at a mediocre job because there just weren't any other options: I could either stay at that job, or leave a town I loved.
When my wife and I decided it was time to move (she had just completed her Master's), job opportunity weighed heavily in our decision making process. We had a lot of other considerations (we wouldn't live someplace we didn't like just because it was good for our careers), but we wanted to make sure we at least had multiple options when it came to work, and that is absolutely something the Bay Area provides.