It's an accepted fact by Sims players that no matter how well you think you know the game, sims have a mind of their own. Sometimes you can wrestle them into behaving the way you want with arcane tricks of furniture placement or by installing mods. If you're one of Maxis' programmers, though, and you're in an "ask for forgiveness instead of permission" kind of mood, maybe you just rewrite the entire under-the-hood AI in about a week during development.
Former Maxis developer David "Rez" Graham is now the director of game programming at San Francisco's Academy of Art University but worked QA back on 1999's Sim City 3000, and by the time of The Sims 4 was serving as lead AI programmer. That's AI in the "programmed NPC behavior" sense, not in the generative AI sense.
