There is no sense in NOT selling Bitcoins ever. This crypto shuld bring profit. Until we use fiat money, the best way to spend it is converting them into dollars and Euro.
Almost every one of us who is investing his money into bitcoins and is going for buying of bitcoin wants to make his life comfortable. He actually wants to something big by investing his money in this. If you are not going to sell your bitcoins ever, then there is no point of keeping bitcoins. In fact, you then need to invest your money in some other business so that you may get some profit at the end. Sell your bitcoins but only when you are going to have some good profit.
as far as I know investing in bitcoin is more profitable, so most of the investors are choosing bitcoin as an investment.
now it's been a lot of others who choose bitcoin than other coins that have just appeared in these months.
The fact is most of the people are treating bitcoin as an investment and not a currency and in that case they are not willing to sell their coins to make higher profits in future so even if price is too high now they will not sell their coins now and will wait for the price to go even higher to make more higher profits in future.
If that's the case, until when are they going to hold their coins? How would they determined if they'll keep on holding it when in fact they don't know what will happen to bitcoin in the next few days. It is indeed a good decision to hold their coins until the price go higher, but until when? If there's an opportunity that bitcoin's price is really high, aren't they going to sell it? Will they grab the opportunity or wait again and again? It's a foolish thing if you'll just keep on holding it for the rest of your life. You have to spend it so there will be a cycle process. If majority of bitcoin holders were just holding their coins and didn't even bother to sell it, it will also affect the price of bitcoin. I would like to suggest that they should set a target price as to when are they going to sell their bitcoins.
On the other hand, as what OP says
Point being, selling bitcoin for dollars seems counterproductive. Why convert your paper fiat currency into sound value storing superior bitcoin, only to sell all of your superior bitcoin back for worthless antiquated fiat currency again? Why not just spend the bitcoin itself to buy what you want instead of taking a loss by converting back into dollars which will inflate away eventually anyway?
We can't really spend the bitcoin itself because no one accepts it. There's no mall, nor stores who accepts bitcoin as mode of payment. So people will always convert their bitcoin into fiat because they don't have a choice. How would they spend their bitcoin if they don't convert it?