In my opinion, Bitcoin is hard to become a common currency. There are too many shortcomings, such as lack of stability, low supply, are being used to accomplish some bad intentions. So that really is not qualified to become a currency. I do not appreciate people always want to make bitcoin a currency. it absolutely can not afford!
Obviously, we cannot expect it to just be a currency that will be used by everyone worldwide, as some would basically be limited to its usage, but at the same time, we still have to understand the fact that this is a very new market and there would still be a lot of development to come in the long run, which I believe will bring about real life usage.
We may not be seeing that now yet, because a lot of people believe we have not reached that stage yet and by the time we do eventually, we all know the value will not be the same which is one of the reasons a lot of people would prefer hoarding as an investment tool instead now than a currency, coupled with the fact that with respect to its volatility, it is still very hard to use in the real world.