When bitcoin was early develop, who does expected that it can be the valuable currency just like now. IMO many investor is look bitcoin has a good prospect from their view so it gain more value & trust. Just keep in faith and hold bitcoin because it surely become a good investment on the future
As of now also no country is officially accepting bitcoin as a currency. It is still a new technology so just invest very small % to take advantage if it grows. But do not put all your savings here.
Here I must say your information is little outdated.Australia is the first country which begins to accept Bitcoin as currency.Just few days ago they officially announced that Bitcoin will be recognized as currency from now onward in Australia.