I think we need to articulate exactly what we mean by supportive.  If we mean supportive in terms of exchanges and actual adoption in ordinary commerce, I agree that Japan is the clear leader.  If we mean supportive in terms of ICOs, I prefer those countries that at a minimum will allow you to bind a regulatory authority ab initio to the legality of an offering (so if you can get a blessing in advance and the regulator is bound, you are good).  That right now means Switzerland and a few other places (perhaps Gibraltar).  If we mean supportive of mining, then obviously we need to look at cheap electricity and necessary infrastructure, and to me that is still China.