If a currency hasn't gained mass adoption, I don't believe its a currency. I can claim I have a currency of green marbles and my son lets me buy candy from him with green marbles and he buys candy from a friend with green marbles so therefore its a currency.

I'm not saying bitcoin can't get there, its certainly possible, but when the majority of use cases use terminology like "holding", "investing", "trading" its treated by users as more of a security/equity than a currency.