You have a few engineers with hurt feelings and Apple lost the potential for some contributors to fix issues (at the expense of security by obscurity).
It does sound like a big deal until he quietly mentions half the engineers hired we’re like 3 to 4 people lol.
Darwin is a big deal in that it’s backed by one of the 5 largest tech companies. But when you look at it, it’s essentially just Mach with FreeBSD (NetBSD core utils in PowerPC days) bolted on top.
You have a few engineers with hurt feelings and Apple lost the potential for some contributors to fix issues (at the expense of security by obscurity).
Did the world really need another open source OS?