Would you prefer that one person be horribly tortured for fifty years without hope or rest, or that 3^^^3 people get dust specks in their eyes?

The square of the number of milliseconds in 50 years is about 10^21.

Would you rather one person tortured for a millisecond (then no ill effects), or that 3^^^3/10^21 people get a dust speck per second for 50 centuries?

OK, so the utility/effect doesn't scale when you change the times. But even if each 1% added dust/torture time made things ten times worse, when you reduce the dust-speckled population to reflect that it's still countless universes worth of people.