It's an unfortunate truth of our society and business culture that we see these things as linear, hierarchical progressions rather than what they are, different roles with different purposes. Just like in the educational sphere we see High School < Bachelor < Master < PhD, there is a tendency to see technical < managerial from a leadership perspective and managerial < technical from a technical perspective. I wish we would move away from that stupid way of thinking. Devs are one role, PMs play another role, managers, directors, VPs ... they all should be serving distinct and different yet essentially equal roles, yet we see it as a competition and instill an artificial hierarchy. It's really only a symptom of a larger social value structure thing though, so it won't change any time soon or without a disruptive process in between the two states.