simple: it's arrogance. lots of examples come to mind: Francis Crick and race, Freeman Dyson and climate change, Elon musk and literally everything :)
So maybe you're underestimating abilities of some people to master multiple fields
If Elon Musk built a 3 star Michelin restaurant himself from scratch then yes I would classify that he has mastery of the fine dining industry. You could be an amazing chef but couldn't run a restaurant if your life depended on it. Just like how there are brilliant engineers that aren't good at being CEOs of a tech company.