Entrepreneur vs High Tech Entrepreneur: This is a reasonable distinction, so I'm going to only talk about high tech. High tech, to me, means, the internet plays a key part in the product, and in my case, it is where the entirety of the product lives. So, software and virtual goods or information or services, rather than a factory and manufacturing, etc.
Labor Pool: The labor pool for a high tech company is global. I don't care where an employee is working, and the companies I admire are very globally diverse. This is becoming increasingly common it seems- for instance one engineer I know of is living on a beach in Thailand working for a US company ostensibly based in Boston (but with employees in at least a dozen countries and states.)
So, the labor pool is global, for high tech businesses (not so much when you need a factory.)
Funding Climate- Yes, if your business is selling stock in your business, then you want to be located within an easy board meeting commute of Sand Hill Road. But one of the aspects of high tech business these days is that the funding needed is vastly smaller than before... you can self fund if you're a highly paid employee who lives frugally and puts away $40k a year for 5 years, for instance.
There does seem to be a segment of the population that thinks "high tech startup" is only that segment of companies that are trying to be the next facebook-- that is, bets on really long odds that require large amounts of outside capital. I think that's kinda silly when you can self fund and pursue businesses with much better odds, and thus have risk adjusted returns vastly higher. (would you rather have a %1 chance at being a billionaire, or a %75 chance at being deci-millionaire?)
The large, homogeneous, wealthy market of the USA: Can be addressed by businesses anywhere. There's no need to locate in the USA to address the US market. Further, in many business areas, the US market is less than half. For instance, I'm currently earning around %35 of revenue from the USA, with the majority coming from overseas, non-english speaking countries, because I simply took the time to translate the product into those languages. I don't even know the cultures, and haven't advertised to them, etc. But they are the majority of my income.
I think the USA wins on venture capital, sure, but loses in just about every other regard.
Plus, if your company has X amount in capital, would it be better to be located in the Bay Area where your burn rate will be 6-10 times as much as it might be in, say, Thailand?
I know americans think that America is number one in a large number of areas... but once I left america, I started to see that the american perspective on the world is pretty distorted.