It's one of the most common things I see, and it makes complete sense when you think about it. Technical specialists - engineers, scientists, clinicians, IT professionals - have built their careers on being brilliant at a specific thing. They've been rewarded for their expertise, their precision, and their ability to solve problems independently. Then they get promoted into management, and suddenly the job is entirely about other people.
The skills that made them exceptional in their specialist role don't automatically translate. Leading people requires a completely different set of abilities: listening, adapting your communication style, giving feedback, having difficult conversations, motivating someone whose priorities are different from yours. These are often labelled ‘soft skills’, but they're genuinely complex, and most technical specialists have simply never been taught them.
The good news is that they absolutely can be learned. And technical minds, once they understand the logic and the evidence behind great leadership, often make the most committed and effective people leaders of all.