Yes if its allowing us to make profits then there is nothing wrong in selling them, as we are investing our money in it only to make profits and if we never sell our coins then how we will experience the success of making profits from it.
I agree why you are going to stop someone from selling everything if that is going to be their main source of living? Or you just wanted them to keep holding the bitcoins that they have so when the price is going to increase they are going to earn some interest rate as they are just going to hold it for a longer time.
If bitcoin is only source of your income then you will never prefer to hold them longer without selling them as you need money for your expenses so you will surely sell when you see higher price.