Believe me, even those who say that don't know clearly: why did they have that thought ^^
As long as you achieve your goal at the moment of selling that crypto, you are clever & successful. Maybe the profit makes you satisfied, maybe you invest in a project that is more profitable, or you simply want to convert crypto assets to fiat for use in life.
Imagine, you sell 1 BTC to invest in a liquid DeFi project, and your assets x100 times after a week. You can use that profit to buy 90 BTC, and create a 10 BTC bounty campaign to share the joy with the whole community

In the bounty hunters there may be people who claim you "It's stupid to sell 1 BTC" ^^