I believe that BTC is both an asset and a currency. Some people use it for their everyday payments as a currency and others to hold value (asset).
I also think when more merchants start to accept BTC or any other altcoin as a form of payment, people in general will be more comfortable to use it as currency and eventually BTC will replace fiat.
Few people anymore actually use it like a payment currency anymore unless you are rich and do very major sized BTC purchases