The answer is pretty simple.

All three examples you listed had hit the rock bottom in term of economic development with low GDP. As long as the government gave the economy a chance, it had no place to go but up, not to mention that one benefit of autocracy over democracy is its efficiency. As their economy grows, all 3 countries are moving towards democracy. Even though all three countries experienced slow down of their economic growth, all of them have evolved into more stable and mature societies.