Verdande
First Post
AD&D is, perhaps, a relevant example of where it's still quite hard work to pull together a decent homebrew setting and scenarios quickly. If it worked like Sims (on some levels) you'd have a basic setting (Freeport-ish), then you'd drag major NPCs in, carrying with them a 'cluster' of underlings and organisations. Then drag/ overlay several events/ missions hooks . . .
Not to quibble, because I really like this discussion, but AD&D is pretty easy to throw together decent homebrew quickly. See, all you do is think of a place like Freeport, "borrow" some major NPCs in, who each have needs and organizations... It's even easier inside your head than on a computer screen!

One of the biggest strengths that tabletop games has is DMs who can think on their feet and make quick rulings about what happens in situations that nobody could have seen coming, such as what, exactly, happens when your players try and push over a throwaway altar you stuck in a dungeon for "flavor", or when they capture and try and befriend a bandit from a recent skirmish.
Until computer games feature that kind of flexibility and quick, on-your-feet thinking, DMs will have the advantage. That day may not be that far off, but I can't think of a single person who would rather follow the "adventure path" than decide that maybe the quickest way through this dungeon is through this wall, or that they'll side with the necromancers instead of the goody two-shoes Stock Kingdom X.