That's also a form of 'decentralization'.
In all seriousness, it feels great to know that one country isn't the other when it comes to being open minded towards new emerging technologies. On the other hand, I am sure that when Japan has been booking consistent GDP growth through Bitcoin alone, other countries will follow. It's impossible for any well thinking government to ignore that.
Seriously, not allowing crypto currencies to develop in your country does more damage than allowing them to develop. If we take into consideration that it is a perfect hedge as well for governments, then they are even more stupid. In case the regular economy implodes due to their shitty fiat system, which is quite realistic to happen, they won't be hit as hard with crypto offering an alternative form of growth. Japan is smart, very smart. I'm looking forward to their GDP statistics for 2018.