I think that, in other countries are that are not supported, is that the country banned them?, or they are not recognized by their central bank. Maybe the local governments are not aware with it, so bitcoins are not supported with them.
Even if the government knows the existence of bitcoin, why would it support it? they will not get anything from it. Bitcoin is not meant to be for the government, that is why it is decentralized.
It could lead to some countries who are not being aware or updated to new technology will be late for their new innovations of other countries.
Countries has their own way to know technology, and much faster. But they have other things to prioritize in their economy than to upgrade their money system.