I just read the article and realised that the top users are also from the world economic or political powers such as the US, China and Russia. This is also due to the level of awareness and technological advancement which the citizens have taken advantage of too. You won't expect people from poorer countries to have easy access to such information and technology.
Well people from poor countries are mostly late to get some infomation about something like this.
And most of the time they couldn't risk their money if their isn't too much info about it.
Most of the time they would just invest when it is already well known or being trusted by many people.