It's a Mach microkernel and a BSD userland taken from FreeBSD, which coincided with them hiring the founder of FreeBSD into a role to do release management. He's left since.
The fact you don't know this suggests you might not be aware of macOS fundamentals, the history of OS X, or MacOS that preceded it, the design decisions that went into all of those, the user groups they targeted at key points (including the adoption of FreeBSD userland), or their overall design intent.
I therefore struggle to agree with your premise that it's "not designed for pros", or that you are qualified to make that assertion.
It's a Mach microkernel and a BSD userland taken from FreeBSD, which coincided with them hiring the founder of FreeBSD into a role to do release management. He's left since.
The fact you don't know this suggests you might not be aware of macOS fundamentals, the history of OS X, or MacOS that preceded it, the design decisions that went into all of those, the user groups they targeted at key points (including the adoption of FreeBSD userland), or their overall design intent.
I therefore struggle to agree with your premise that it's "not designed for pros", or that you are qualified to make that assertion.