As a player, I've definitely thought of asking that question, but I restrain myself out of politeness (I know it isn't easy to be a DM).
As a DM, it's been a
long time since anyone has said anything, and hopefully they're not thinking it, either. I try to guard against it several ways:
- I run a sandbox-style game that might be described as "points of light." That is, there's wild lands with a few safer spots of civilization (city states and holds of one sort or another). Some of the "leaders" are higher level, but they tend to have responsibilities and immediate concerns that make it hard for them to go running off on adventures; it's easier for them to sponsor agents with more freedom to act.
- I tend to avoid "save the world" story hooks. The default motivation for PCs in my game is "fortune and glory." It invariably gets more convoluted than that as play goes on, but that's still often the main thrust.
- Few NPCs are classed characters, in my game. Almost everyone is "0-level" normal men. Most nobles are 0-level (the classed ones are the guys who hacked their own barony out of the wilderness). There are plenty of holy men and priests, but they aren't Clerics. (They might even be able to "perform miracles," just not by Cleric spellcasting rules.) I assign special abilities to 0-level NPCs as needed (e.g. the tailor is a 0-level man who has taught himself to shoot a crossbow like he's a 4th level hero).
- I *do* have NPCs trying to do the same stuff. However, since the goal tends to be "fortune and glory," this tends to be viewed as competition, not assistance!