China is the largest smartphone market in the world and most of the major OEMs are domiciled in China. This gives the country the privilege of being one of the first smartphone markets to try out a new technology. Furthermore, the Chinese models of most devices are cheaper than its global counterparts which compatible with multiple languages thus cust more. In other to try out a new tech first-hand, smartphone enthusiasts sometimes buy the Chinese model (especially when global ROM is not available) and then flash the global ROM on it. People also do this because of the cheaper cost. This is about to change, at least for Xiaomi phones.
Gizchina News of the week
Xiaomi fans are not happy about this but we hear that it is still possible to flash whatever ROM you want on phones with an unlocked bootloader.