Seems to me the major reason is that the hardware manufacturers are from Spain (BQ) and China (Meizu). There might also be license/compliance issues or software

Seems to me the major reason is that the hardware manufacturers are from Spain (BQ) and China (Meizu). There might also be license/compliance issues or software patent problems that hold up a US release. And my guess would be that the Chinese smart phone market is actually bigger than the US one, especially for the price point of these phones (and Europe is probably not that far behind the US).