Indeed it must not be sims-like. This sort of thing would not add to the iimmersion or the atmosphere but to tediousness. It is really the same reason why mandatory eating and drinking isn\'t ingame: it would detract from the games actual point (adventuring) by adding unnecessary and unrelated tediums. The sims is about staying alive, while PS is about adventuring: two entirely different genres, and what is good in one can very easily be quite bad in the other.
However, the idea is not entirely bad: dirt and such could show on the char. This is a lot more immersive while not tedious. And it can be done without changing models: semi-transparent layers can be overlayed to the rendering, so no specialised \"dirty\" textures for chars or cloths would be needed.
