I think most users are involved in Bitcoin not because they belief in the technology, but because they hope the price will go thru the roof. So let us say the price would be at $900 for the next 50 years.
Would you still use and buy Bitcoin or would you leave?
EDIT: Poll added!
I will still use it, obviously if the price were to be stable then some interest is going to be lost especially from investors but it will offer great stability for the development of businesses.