I see where you're coming from, but environment has many subtle factors that lead to, I believe, missed opportunities if they aren't taken advantage of. For example, what would a Houston Oil startup gain from spending a few months of critical startup time in a city with high rent, drastically different driving culture, little access to oil companies, services, equipment, fields and etc, and a completely different set of laws regarding their practice? Better to be spending their after-hours times mingling with the oil folks in Houston bars than the tech folks in SF bars.
Just to clarify my statement - for some companies, it makes complete sense to stay in their local territory (think a young Alibaba). For some others, it doesn't. It's case by case.