Doesn't follow, you don't need to grade linearly, i.e. you can consider avoiding corporeal or mental damage / anguish above a certain threshold exponentially more important than avoiding dust specks.

Think of an AI taking care of a nuclear power plant, consider it has a priority system: "Core temperature critical? If yes, always prioritize this. Else: Remote control cleaner bots to clean the facility. Else: (...)" Or a process throwing an exception which gets priority-handled.