If Bitcoin became universal that also means we live in a decentralised economy.
That would be very great, i hope i'm still alive to experience the situation.
I do not think it can happen ever because it means that country's currency will come into danger as they would like their currency to remain stronger in the world which benefits them. Thus as btc is not any country's currency it would not really help the government and thus they do not want to make it legal in their country.