Some people make the mistake of selling all there Bitcoin just because they want to start a new business or investment with the money and after selling it and the start there new business or investment some time later it crashes and they lose it and also lose their bitcoin investment so keep your Bitcoin investment going while trying out other business or investment.
Selling our holdings at once is never a good practice, I'm sure that Majority of this people that like selling all there bitcoin are those Investors that have not accumulate enough stash of bitcoin in thier portfolio they feel that after selling it that it won't take long to accumulate it back.
While those Investors that have been struggling to reach the status of overaccumulation can only sell 5 to 10% of thier holdings whenever it double and after that will have to allow it to compound upon itself before attempting to sell again, because they know how Long it takes before they were able to reach the status of overaccumulation so they wouldn't want a situation where they will start the accumulation process all over again.
Where did you get this whack strategy from? It's important you don't sell your Bitcoin within your accumulation phase. It doesn't make sense and it would be dragging you behind and reducing your success rate at reaching your accumulation target ASAP.
If you continue targeting the price increase and shaving profits of your portfolio as an investor still within your accumulation journey, then you're the same as a trader since you've the short-term profit taking mentality and this isn't good for your portfolio and on the long-run you may see clearly that you've succeeded in selling much BTC too soon because you had your focus on the wrong criteria for profitability which should be having more quantities and holding for a long-term instead of going for short term profits.