A good manager doesn't have to be a technical person, they have to listen to their subordinates. When you tell your manager that something can't be reasonably fine or shouldn't be done their job requires them to listen to the technical experts on the project.
I've been on both sides of the managerial fence, and in my experience, you can't have one without the other. A good manager can't listen to their subordinates if they can't understand what they're hearing. It's like explaining color to a blind man. One of the primary responsibilities of a manager is communication. He or she has to be technically savvy enough to not only understand the decisions his direct reports are making, but be able to translate those decisions into the appropriate level of technical detail to the people he or she reports to. And that coin has two sides: a manager must also have enough business savvy to understand the decisions of his superiors and be able to translate them to his direct reports.
A manager who makes decisions on the say-so of his subordinates without being technically conversant enough to actually understand and explain why it's a good decision, isn't a manager at all: she's a proxy. The same goes for a manager who just tells his reports what to do without understanding why his own managers want him to do it.