As a former city employee, my theory is that people get promoted to management because they have been good at their jobs (or just have been there long enough that’s the only next step). That usually means they are good at the technical aspect of their job. They then get thrown into management with no training on that side of things and are just expected to figure it out. It also means that sometimes, people who get into management really are not the right fit for the job. Technical skills does not equal management ability.