It's not as miraculous as some people in the US will go on and on about. I mean, it is definitely a useful plant but it's legal in many countries and hasn't become a major crop.
It's not technically legal in any country because of a UN treaty. I think part of the reason it hasn't 'taken off' in countries where laws aren't enforced/it's decriminalized/etc is because you can't transport it over the border, you can't sell to big clients in America (or anywhere else), the laws regarding distribution on such a large scale aren't clear enough even in places where it is "legal" so no one wants to put all their eggs in the marijuana basket at this point.