Actually the reason Bitcoin cannot be used as a currency like the country's currency is very simple: "Bitcoin is not real, it cannot be held and printed" whereas money like dollars can be printed every year, Bitcoin has no real place, money like dollars has a real place.
Bitcoin is like a dream for you, but it sure is.
I'm disappointed in hearing a bitcoiner(community member) boldly saying bitcoin isn't real. Bitcoin is more of a currency than the fiat can even be. For starters bitcoin isn't just printed from thin even when ever the economy (price) is down to boost it unlike the fiats that the government body abuse for their selfish interest claiming it's for the good of the masses.
Bitcoin has a finite supply and been purely backed also very transparent unlike the fiat system that doesn't have any of this. Now between a currency that it's mode of operation is visible and can be verified by all with the required knowledge than a system where only the banker make the important discussion, which is qualifed to be called real money?
Bitcoin is very young, the fiat currency are centuries old, therefore you don't expect bitcoin to just come into the spotlight and start dominating every aspect of the economy, it's a gradual process that'll take time to happen.