Perhaps it is irrelevant. (And I don’t have the 4e DMG anyway.) But it seems to me that Wizards never expected the skill challenges section to be examined and debated the way they did—say—the combat system.
Isn’t this little more just a “hey, here’s roughly one way to do some stuff”?
More than a little, it is exactly that. Yet some refuse that a way other than their reading is even a viable approach.