Why would any serious developer use closed-source code they can't debug and modify? Especially for a production server?
It's the same reason no serious developers or hackers use macOS, like part of the point of being a developer is being able to dig into the code at any layer and debug and fix things.
That being said, my point isn't that Apple should absolutely focus on making a server OS again. It just saddens me how far behind macOS has fallen as they stopped caring about the fundamentals; back in the day, it would be Linux trailing behind macOS. Nowadays, you can't even have multiple routing tables on the latter, the firewall code was probably last updated in Snow Leopard, and what Apple happily shows off on WWDC is a wrapper around Linux. Something functionally equal can be cobbled up together by anyone sufficiently experienced in minutes, using just Bash, OpenSSH, and QEMU.
I really wish macOS would let me have a similar level of control over applications as Linux with namespaces, without me having to do all the heavy lifting.
If they were to support darwin containers, what would be the point? Literally nobody would build to it, Linux won.
because nobody does ci/cd against macOS or iOS apps right?
There aren’t any app developers avoiding the Apple ecosystem because there aren’t Darwin containers. They don’t sell server hardware and by all accounts have no intention of ever reentering that space. So they’d spend a bunch of developer cycles to reduce their own revenue stream with no apparent upside beyond “goodwill” which they’ve never been overly concerned about.
If they're investing resources into it regardless, they might at least try making something that Docker for macOS and co. haven't solved the same exact way already. Something that, due to their almost unhealthy obsession with "system integrity", only they can realistically make. Like native containers.
Which is a ton of ‘em.