Nah, I had beds and wasn't moving them around jobs.
I'm convinced that it's a bug related to the policies system. Because as I said my girls kept going to work with a bad mood even though I forbid them from doing so.
Taking a brief look at the code, with the caveat that I don't really know that much about this stuff, I'm not seeing anything that should blanket effect everyone. By that, I mean all it really seems to do is force rest for people with the selected mood(s) assigned to "unhappy jobs", which it defines as milk barn, night club, quarry, and streets.
If only those people are getting unhappy, I may be misreading the code. If other people, such as the maid, mistress, mechanic, doctor, teacher, hunter, etc. are getting unhappy, it would appear another mechanic, though possibly a hidden one ie one not listed in a changelog, is to blame.
I know I've dealt with this same thing before, but it was back in August or September. I never did find a solution, but I never tried very hard to find one either. I've since started a few new games.
Edit: I've been digging through to see what modifies the "happy" value of NPCs and one that might be causing it is food. Even if there is enough food to prevent starvation, and more than enough food generated daily to keep people fed, each night the game runs a check. If the total amount of food you have is less than the number of slaves + guests, then happiness for everybody drops by 2. Every weather event also has seems to decrease mood.
Add to that the fact that it seems the only ways to increase mood involve sex (consensual (unless masochist) and involving or at least observed by the MC), positive interactions with the MC like working out with him, and champagne, there appear to be a decent number of ways this can drop in the background, but not a lot of options for increasing it.
Looks like the game also runs the code to feed everybody, then the food gains for the garden, then the check to see in you have at least as much food as NPCs, then gives you food from all other sources (shop, hunting, etc.). So I guess my advice would be make sure you have more than enough food and do a group workout or throw a party every few days. This should gradually improve everyone's mood.
I admit there could be something not working right that I'm not seeing, but I'd be interested in hearing if Doing those two things alone got someone out of a colony abandonment spiral.