The simple reason why most RPGs don't implement requirements for things like Food and Drink (and Shelter) is that they aren't fully developing those Roles which are portrayed, because they derive from hack-and-slash. To implement them requires changes with certain aspects of the game world, such as considering how much time players would spend on their characters' hunger and thirst; most designers would rather not bother.
If F&D aren't necessary for survival, then they become little more than bonuses or salves. The only reasons which I see, then, that these things are done in the wilderness of PS:
- as props for RP, which most of this community already does anyway
- efficiency while questing, viz. while grinding
As far as goes a basic run-down of that stuff, anyway. In conclusion, I don't think PS as it is now would benefit much from developing wilderness survival skills, and requiring them sans changes to the game mechanics would break it.
