My problem with that stance is that some problems are just beyond human's abilities, period.
Example: if Galactus decides that the Earth looks yummy, wtf could human people do? Even assuming that they could eventually come up with a way to defeat Galactus (I doubt it, but let's say they could, for the sake of argument), it would take them a long time to get ready. They'd never make it in time.
And what if aliens invade the Earth with overwhelming forces? Should humans be left alone to fight off a much more technologically advanced and much better-armed army, as surely facing such an invasion would eventually led to their development and to a better future? That worked so well for Native Indians.
Plus, even on a much smaller scale, call it dependency or whatever, but if I were assaulted by a criminal I'd be damn grateful to any superhero who could give me a hand, I certainly wouldn't think "hell, no, why couldn't a human cop save me!?"