these AI problems are one of the things that makes it so hard to like ts4, especially when they advertised the game with "the smartest sims ever". they knew they weren't yet they decided that scamming people was a good idea.
the game code is a flawed mess due to the change of plans it had and i think it's one of the reasons devs keep ignoring some popular requests, because they can't fix it thus they can't make them. i don't know if it's because they don't have enough skills, if it's pure laziness, ea's decisions, arrogance or if it's a truly irreparable game. though, some modders have been able to soften some of the issues, while also making features that devs said were "impossible". which gives the feeling that devs ain't even trying.