This is of course is the primary reason:
Meet girls.
The world was in need of a ubiquitous currency for free trade in the global economy. Sooner or later one was bound to show up. My thought would have been a World bank that would have fleeced the public just as the current institutions. thankfully Bitcoins came into existence that is not controlled by the 1 factor that has corrupted every other previous institution and system, humans.
Bitcoin is an untethered currency controlled by math that is fully transparent to the users. The greatest thing about it being controlled by math is as my 3rd grade teacher taught. Math is either right or wrong, and there is no grey area to be adulterated.