A manager has to have the right skills to manage a project and lead people. This is usually not something you find in engineers, so like teachers, it's not the expert knowledge (e.g. tech) but soft skills that count most for a manager. Therefore, a great manager doesn't have to know to code, at all. I haven't seen a single dev lead who got promoted from developer to manager who actually managed to manage the team/project reasonably.
I would like to be offered the choice. That is, most managers come from "the business" or something, and have never been an engineer, and don't want to have been an engineer. Given a choice, I'd pick the manager that was an engineer, but those folks are pretty rare.