I think that's because at the early stage bitcoin was mainly supported by IT-enthusiasts and libertarians who had a profound knowledge and interest in the theme, as you can afford digging into staff like that and invest when your living standatds are high. However, when you live in a poor country and have to toil whole day to make for living, not much time and interest is left.
I find you thought a good one. Another reason is, Bitcoin originated in a country where people are open for a change and technology evolution.