A lot of managers were well-performing ICs that got a promotion, either because a manager position needed to be filled (and they were the least bad option) or t

A lot of managers were well-performing ICs that got a promotion, either because a manager position needed to be filled (and they were the least bad option) or they needed to be promoted to keep them (which in some cases is the only way to give them a raise). Neither of these means they have even the basic skills to be a manager at all, let alone a good one. Unfortunately since these types of managers don't recognize good manager skills, they'll go on to promote more unqualified ICs below them into manager positions.. and the cycle repeats.