Ofcourse the usercount is going to become more stable in future, at some point the market is going to become saturated and the amount of new users getting into bitcoin each day will start to decrease until we reach a stable base. The usercount can't increase linearly or exponentially forever, I'm sure you would have to agree with that as well. So the increase in usercount will slow down as well as the amount of new coins and thus we are going to reach a state of equilibrium eventually. It's just a matter of time.
I don't see it like that.
The nature of bitcoin itself keeps any stability from forming when taking into account the price and the amount of users. The main thing (almost the only thing) that attracts people to bitcoin, are promises, that if they buy now, then they can sell later with a lot higher price. That creates this situation where stability is impossible because as soon as the situation becomes stable, then people won't get what they came for and they will start selling/leaving.
Bitcoin has to be either on a rise or dropping, there is no stable middle ground.
The fundamental flaw here is that a currency shouldn't be attractive as an speculative investment. It ruins the stability, and stability is the main quality of an good currency. A currency should be unattractive as an investment, so it will only be used to transfer wealth and not be considered as a source of wealth by itself.
