It all depends what your industry is. If you're an entrepreneur founding a startup of any kind, but especially one that will require software developers, you're getting a huge benefit from the entire ecosystem of Silicon Valley. That ranges from access to capital to access to human capital that you really can't get anywhere else. The cost of doing business is well worth the price. Moving to Boise, as beautiful and inexpensive as it is, just isn't an option. Same thing if you're on the human capital side, a good software developer in Boise is just seen as an engineer and paid accordingly while a good software developer in San Francisco can make significantly more, even accounting for the cost of living difference, plus share in the upside of the company they're helping create. Plus CA is the only place in the U.S. you can live and get that combination of climate, culture, and access to the range of outside activities that are there.
Bottom line, if you're working at McDonalds in Modesto then the taxes and regulation in CA probably aren't worth it. If you genuinely would rather live in Boise than CA, then by all means you should. If you move to KS only because you save a few percent in income tax, you may be suffering from some loss of perspective.
As for the OP, 10K businesses leaving (although it turns out just opening an expansion office elsewhere is considered "leaving" in the study) over 8 years says absolutely nothing about the state's viability for businesses. How many businesses move to California (or opened a branch office in CA) during that time (this article would suggest more than left
http://www.scpr.org/news/2015/04/07/50825/the-myth-of-businesses-leaving-southern-california/)? How many new businesses start in CA each year? From this SBA statistic it looks like about (
https://www.sba.gov/sites/default/files/advocacy/SB Profiles 2014-15_0.pdf) 240,000 per year. If 1,250 of those 240,000 are leaving per year, it means that less than 1/2 of 1% are leaving per year, hardly an exodus. Of course all of those numbers need context to see the kind and size of companies that are coming, going, and growing in the state. Don't get me wrong, I've started two companies in CA and am actually part of the .5% that left, and the taxes and rules were certainly annoying, perhaps occupying a fraction of a percent of my time/attention. But I didn't leave because of them and if those are what make or break you than you were living on the edge all along anyway. I'd submit that the vast majority of those trying to paint CA as a runaway big government gone wrong haven't run a business both there and in a genuine small government stronghold, like say Mississippi or Kansas, and certainly not a high growth startup.
