This is more of a regulatory issue than anything. Airspace is very strictly controlled in both countries. Further, outside of NA and Europe, GA is simply not a

This is more of a regulatory issue than anything. Airspace is very strictly controlled in both countries. Further, outside of NA and Europe, GA is simply not as commonplace and in many cases like China/Russia, it's because it's (for all intents) inaccessible. Besides being heavily regulated, it's also relatively expensive, even by first-world standards.