While you are hoarding your bitcoins your own wallet you are protecting them from being dumped in some time, because you are the only one who has a full control of your own bitcoins.
I dont see anything bad with this, you are keeping those bitcoins and you are not selling them... And it is like an investment because it's price is always going up.
But holding fiat is not the same, maybe you are confused because of that.. quiet money in fiat is always a bad thing.