I've never know immediate management to understand the business nor the system as well as the ones with boots on the ground. I've yet to see a situation where the manager doesn't end up coming out of his office and asking someone on the team "so, what's this mean?"
It's not management's job to understand details of the code (and it's probably a problem if they do). And it's not their problem to understand the business perfectly (and it's probably a problem if they do). It's their job to facilitate getting work done. That means helping their developers work as effectively as possible. And in most cases, that means keeping customers from end-running around whatever work management process is in place. If you're doing agile, the manager's job is to protect the iteration, and shield the developers from politics and pressure so they can work well.
I often use a bread-baking analogy here. Making software is like baking bread. This iteration, we get some flour, water, yeast, and salt, mix them together, knead, rise, and bake. And if someone comes in five minutes before baking is done and says "Can't you just add some raisins now? It's just a handful of raisins, it's not much work". No. It means starting over.
