It would be interesting to correlate these rankings with the levels of ethnic diversity and with the rates of immigration into the countries involved. It's easy to hypothecate political differences as a causal factor but a lot of other covariates are at play, too.
Rent seeking by would be developers. Terrible idea to just put subsidies out there. Governments spurred development of aviation by offering prizes and mail contracts only when certain objectives were achieved, no generalized subsidies just to fly. Even the railroad incentives were not just cash subsidies. They gave away land, which was all-but worthless to the recipient until the recipient created an economically viable railroad to reach the land.