Also I don't find jobs / people in the state the most accurate indicator. To someone living in LA, moving to SF might as well be moving to Utah. The open positions / qualified people is the far more useful metric, and SF will still beat all of them on that.
I could easily live somewhere cheap and commute for a few years then build up enough to move somewhere nicer.
What irritates me the most is there is absolutely no physical reason why London has to be the place for start ups in the UK and a whole bunch of reasons why it's not a good place.
Where I live now rent and house prices are incredibly cheap (even compared to most parts of the UK), the city is rolling out excellent fibre (I have 150Mbps at home and 100Mbps at work) and transport links are excellent, it would be a good place to start a software company (I am doing) but hiring is going to be hard since it will require relocation to get the talent needed (or working entirely remote, something I'm considering).
I am in security (but it's similar in many specialties) and while there are very good companies in Austin if I want to to rise become a security architect or director of information security I have to go to the tech headquarters. Companies like Google and facebook may have regional offices but the core innovative security/ai/pl work and executive decision making is being done in the home campuses.
That being said, I would never leave Austin for the SF bay unless it involved a $350k+ salary.
San Diego, for example, stomps all over Austin in terms of software jobs, and Austin's hardware scene is laughable.
Big ones: BAE, Northrop Grumman, and General Dynamics. (Previously I would have listed Qualcomm ...)
A zillion biotech startups: I drive past at least a dozen near here every day: https://www.google.com/maps/@32.9104712,-117.2304182,18.57z
Rockstar San Diego seems to be hiring as far as I can tell.
In addition, a lot of manufacturing companies up in the San Marcos/Vista area all need automation programmers.
If you're not finding SD companies with software jobs, I'm very surprised.
It's simply where the most opportunities are. The idea is to move there and live uncomfortably until you network your way to an awesome, high paying job.
Alternatively, the tech companies there usually do more interesting stuff than in other area. Here in NYC most are related to advertising or media—stuff not easy to get exited about. San Francisco has its large share of silly ideas for companies, but it also has many that do interesting stuff.