It really isn't. Just like a well-designed city is not the best map or the best directions. If you asked someone for directions and they started explaining the entire layout of the city instead of just telling you where to go, would you say, "Thanks man, those were the best directions I've ever been given"? No, you'd probably ask someone else.

It's sort of a 'teach a man to fish' problem. If someone is standing on the corner of a hypothetical 14th Street, and if the layout was something like "the Streets run East-West, and the numbers go up as one goes North", it's probably worth their while to explain this. And if the city is designed such that all the avenues are alphabetical from East to West, I'd probably mention this as well.

Personally, I greatly prefer to receive directions that include some redundancy and background information. And yes, every now and then I think "Wow, those were great directions" when someone gives me an explanation that increases my knowledge beyond the narrow scope of my question.