This is only a theory, and I might be wrong, but when I check in on my families during their 'night time' they always are tired and or exhausted. But after an hour of their 'day time' they start to nap and it sorts itself out.

Are the players who are sick of seeing tired & exhausted peeps playing the game during their 'night time'?

If so, I would try reversing time and playing their 'day time' as it's more fun and they are less tired during the day.

When you think about it, we are tired & exhausted at night, and we just walk around watching TV etc, which is what they're doing. By day time (after coffee for some of us), we are more bright & less tired.

Just a theory anyway. The game is certainly not unplayable, as you can just leave them tired & exhausted during the night and they sort themselves out during the day if you praise naps.