You have to remember: you are supposed to teach them. If you stay up for 3 days building/collecting they'll think it's the norm. Try sleeping every night for about a week when you add a new girl and she'll probably figure out, "Hey! I'm supposed to sleep".
A lot of it has to do with the traits (Desires) you give them as well. I tried Wealth in a couple and they tended to push themselves to collapse.
You just have to find the right combination of traits, training and skills to make them the way you want them to be. I've just about found it for me with my girl Friday but having them all the same would get boring quickly.
If all I wanted was a meet and fuck game I'd play HS. *shudder*