I've tried to decipher this, and have come to the conclusion that good children don't become NPCs, only those who come from traumatized households do.
I will have to dwell on that for a while. I suppose it could be another little Maxian 'joke'. You marry your 1 in Neatness Lothario descendant to a 10 in Neatness maid in the hope of getting kids who will help you tidy-up their father/mother's mess, only to discover the maid's really only got 1 in Neat (Don Lothario's descendants get everywhere) and you end-up with a load of kids to clean-up after as well as your spouse ... that sort of thing. Very funny, if so. Hilarious, in fact. NOT.