Well okay, but if you hodl your bitcoins forever what impact does it have on you, on bitcoin, on economy in general? If money don't flow they are dead. If you want bitcoin to become stronger and be wider spread it should be used in different purposes all the time, the more often the better. It both gives sense to bitcoin and makes it more attractive to potential users.
Selling and spending are not the same.
What I mean by selling is when you buy BTC as an investment, to sell at a higher price. Nothing wrong with that, but selling for fiat means you're part of the system. You're using their fiat money, on their terms.
When spending, you're circumventing fiat. You're participating in a circular, Bitcoin economy. KYC-free and without taxation if you so choose. That's a big difference.