Why should the AI be made to emulate a person naive to extant human society, tropes and customs? That would only make it harder for most people to use.

Maybe it would have some point if you are targetting users in a substantially different social context. In the case, you would design the model to be familiar with their tropes instead. So when they describe a character iconic in their culture, by a few distinguishing characteristics, it would produce that character for them. That's no different at all.