There are indeed many people all over the world with programming knowledge; there are far fewer with experience on a technically sophisticated project. The latter class of talent is highly concentrated around the hotspots of sophisticated technical companies which, on average, keep their most important teams in the US.
If you are just reading and writing rows on a single instance of MySQL you can get all the talent you want from just about anywhere in the world. If you want to roll your own fault-tolerant distributed filesystem your options are (statistically) much more narrow, because anyone who can do that is likely to have been tempted by an offer to work at, e.g., Google in Mountain View.