It's ironic that the No. 1 nation on the list accepted Bitcoin as a legal tender, while in the second Bitcoin is not accepted by the government and actually is banned in bank transactions. This goes to show that the while government acceptance helps to make citizens more receptive of Bitcoin, the citizens can choose to adopt it regardless.
I do not know much about the other countries on the list, I have read that Switzerland is friendly to Bitcoin. And in Canada, there was an incident recently where the gov't was freezing accounts, could that play a part in the search boasts?
This is why I have always thought that while reaching legal tender status is without a doubt good, bitcoin was designed to operate regardless of the opinion the governments of the world may have about it.
And if the economic situation becomes even worse then I would not be surprised to see many countries banning bitcoin, however if bitcoin at that point in time is a more reliable currency than the fiat options available to them then people will use it regardless of the legality of bitcoin at that point and the consequences they may suffer, so when we see it from that perspective it is not that rare to see Nigeria as the second place on the list.