Good management is rare partly because nobody wants to take risks and hire inexperienced management.

This leads to a reluctance to promote people without previous experience into management roles. This in turn leads to a shortage of experienced managers.

Good management is rare because it's the wrong people doing it. The bigger problem is that we're all always told that we need "professional" management, implicitly people who's been to "management" schools, this dissuades promoting from within (that honestly can be equally disastrous).

The upside of people from within is that they know what the bottom line comes from, there's been some highlighting of the effects in terms of the founder-mode discussions.

https://paulgraham.com/foundermode.html