Idk if this is a joke or you think hard determinists are also always passive nihilists. That must be the philosophical equivalent of severe depression.

Determinism only technically makes the future unchangeable. Since there's no way to know with certainty what the future will be, there's always the possibility that, for one reason or another, you will attempt to change it from what you think it's going to be, and discover that it was never actually going to be all along. Since humans have no way to know the future and inheritly think in terms of actions and potential consequences, and since the processes that lead to human action presumably also are determined to occur, determinism provides no incentive to act any differently from how you'd act if the future was unset.

lol "hard determinists"

Well, ignorance can certainly be bliss.