Not sure I understand, Mac OS is BSD based. https://en.wikipedia.org/wiki/Darwin_(operating_system)

macOS is XNU-based. There is BSD code that runs in the microkernel level and BSD tools in the userland, but the kernel does not resemble BSD's architecture or adopt BSD's license.

This is an issue for some industry-standard software like CUDA, which does provide BSD drivers with ARM support that just never get adopted by Apple: https://www.nvidia.com/en-us/drivers/unix/

If there were TCO advantages with this setup, CUDA would not be a blocker.

CUDA's just one example; there's a lot of hardware support on the BSDs that Apple doesn't want to inherit.

Why maint other and have baggage ?

Because Apple already does...? There's still PowerPC and MIPS code that runs in macOS. Asking for CUDA compatibility is not somehow too hard for the trillion-dollar megacorp to handle.

Why? AWS manages to do it (https://aws.amazon.com/ec2/instance-types/mac/). Smaller companies too - https://macstadium.com

Having used both professionally, once you understand how to drive Apple's MDM, Mac OS is as easy to sysadmin as Linux. I'll grant you it's a steep learning curve, but so is Linux/BSD if you're coming at it fresh.

In certain ways it's easier - if you buy a device through Apple Business you can have it so that you (or someone working in a remote location) can take it out of the shrink wrap, connect it to the internet, and get a configured and managed device automatically. No PXE boot, no disk imaging, no having it shipped to you to configure and ship out again. If you've done it properly the user can't interrupt/corrupt the process.

The only thing they're really missing is an iLo, I can imagine how AWS solved that, but I'd love to know.

Where the in the world are you working where MDM is the limiting factor on Linux deployments? North Korea?

Macs are a minority in the datacenter even compared to Windows server. The concept of a datacenter Mac would disappear completely if Apple let free OSes sign macOS/iOS apps.

I’m talking about using MDM with Mac OS (to take advantage of Apple Silicon, not licensing) in contrast to the tools we already have with other OSes. Probably you could do it to achieve a large scale on prem Linux deployment, fortunately I’ve never tried.

Well, be that as it may, it's quite unrelated to deploying Macs in the datacenter. It's definitely not a selling point to people putting Proxmox or k8s on their machines.