If the rest of the population wants the bitcoins, they will offer of something in trade which the "hoarders" prefer to have instead of their bitcoins. It's the same as any act of voluntary trade.

Who's responsible for forcing people to create and operate the restaurants where you want to eat? Nobody.

If you and enough other customers are willing to pay enough to make it worth someone's time to build and operate restaurant, then they'll do it.

Who's business is it if somebody decides to refrain, for any reason, from spending their currency? Nobody's.