It is up to them, there is still possibility. What if the first investor in bitcoin will be upset and against bitcoin then it will result for him to dump his thousands of bitcoins and make the price very low. We can't control them and dictate to hold their bitcoins for very long time until we made a decent profit so we can sell first, no, that is not how this game works so it is better to be prepared than never.
Agree. You'll never know what will happen with Bitcoin's value as time goes by. There could exist a point where its price would massively decline, because of dumps or panic among Bitcoiners. In effect, this could make you lose your investments in Bitcoin if you've relied on it as your single asset.
That is why, it is recommended to never put all your eggs in a single basket, but to diversify your investments into other cryptocurrencies. Thus, as soon as you reach profit with Bitcoin, you could sell it for cash or invest it into Gold, to protect your investment from any undesired situation.
Always prepare for the worst possible scenario with Bitcoin, by making the right decision with your investments, and stay safe in the highly volatile cryptocurrency markets. Just my thoughts.
I think it is better to distribute the coins into several such as bitcoin, Eth, ZEC.