I think there may be some hysteresis effect going on here. If wealthy countries developed their tech industry sooner, you'd expect them to have a larger instal

I think there may be some hysteresis effect going on here. If wealthy countries developed their tech industry sooner, you'd expect them to have a larger installed base of projects written using older technologies. This effect explains why Java, C and C++ rank higher in high-income countries. It also explains why Android ranks higher in the rest of the world -- I suspect in many places, people are leapfrogging PC's altogether, and a lot of people have a tablet or phone as their sole device.