Some states are accepting bitcoin even in exchange for their citizenship.
http://uk.businessinsider.com/vanuatu-accepts-bitcoin-for-citizenship-payment-2017-10

Anyway, generally, everything that can increase country's payment balance (lessen the debt) or GDP improves the economy.
Bitcoin itself can really help countries with underdeveloped financial sphere — no reliable banking sector, volatile national currency, etc. Also, it can become a new globalization way for countries under sanctions like Cuba or Iran.