Although there's nothing wrong to sell especially if they think about selling a little percentage of their profit because they really have important thing to spend their money with. But if there's no like this exist and they are just thinking about selling better not to do it and much good for them to focus their attention on buying more Bitcoins since there are chance that they could earn more from it in future.
This is the major reason why emergency and reserve fund are kept aside, you don't have to temper with your holdings because you have something important to do with money, it's only advisable to start taking profit from your holdings when you have gotten to the level of over accumulation, not when you are still in the middle of your accumulation journey, that's a terrible time to be selling off your holdings for any reason.
As a Bitcoin investor, it's advisable to have an emergency and reserve funds set aside so that in case of any eventuality, you wouldn't have to temper with your Bitcoin holdings just because of any unforseen emergencies that may arise in the future.