Yes you are right, people may sell their bitcoin in less value time because may be they think that its price will go more down and will have to face more loss. So they sell them in less value and don't wait for the price rise. But it is profitable to hold the bitcoin when the value is less.
I really wonder when a lot of people talk about selling like they really do not understand a single thing about what they have invested in. Every long term investor should know by now that they are investing in the future and that is what really matters. In the long run, the value of bitcoin will definitely increase more than what we have now and by then some would be wishing for this value just as some of us are wishing we would have been happy getting at $1.