However, it is a good thing not to sell all the holding in the wallet. Selling the whole BTC in the wallet is not a good one. Moreover, what is the essence of holding the BTC when the investor still sells them all at last? Although the investor might have gotten some profits, it is still better not to sell all the BTC in the wallet.
Those that sell their entire Bitcoin are those who do not make provision for emergency fund that @JayJuanGee spent quality time to explain. Without making provision for funds that will support you when things you don't plan for happens, the last resort will always be your assets and considering Bircoin is easier and faster to sell than other forms of investment, it is usually the victim of such situation. Indeed, it is never a good practice to invest in Bitcoin without planning well on how to hold it for long and part of that planning involves setting aside this emergency funds.
I think the other aspects of Bitcoin are to pass over to the next generation, mostly those that are aged. So, even if an investor wants to die and the investor already knows, then there is no need to sell all the BTC he or she has, but it will be good if the investor passes it on to his or her child that already knows what Bitcoin is all about, even if it is a little knowledge that the child has.
This aspect was a hot topic in one of the thread and the discussion there shows that it is not everyone that is invested in Bitcoin that is thinking in that direction. Some that are, have not figured out how to achieve it. While many suggestions have been given, I think every one involved in Bitcoin must put that into consideration. Other forms of physical investments are easier to transfer to heirs unlike Bitcoin that requires some level of secrecy.