You are right that making Terminal.app open source would be a net win for everyone, but it's not going to happen. Not because Apple doesn't want to, but because there's no spare bandwidth for anyone to push for it internally.
I think one of the biggest misunderstandings about Apple is the assumption that they have massive resources available to them, therefore they must have a wide bandwidth for competent development—be that in terms of vision, design, or code. The way I see it, Apple seems rarely able to focus on more than a few things at once. They have never been able to maintain high standards across the full breadth of their product stack.
MacOS tends to get jankier and cruftier with every release. At this point it's akin to a very pretty rug that has had so much mess swept under it that it's impossible for it to lie flat.
If you've ever dealt with the back end of Apple Music (née iTunes Music Store) you'd know that it's held together with a lot of crummy, barely-maintained software that falls apart under the most trivial of circumstances. For example, their iTunes Music Producer software can't even rip two-CD sets without causing file name conflicts in the XML. This bug has not been fixed for over a decade.
Apple does have massive resources. They're one of the highest revenue companies in the world, and have way better margins than most of the higher companies in the list.
At least in the Steve Job days, they'd spin up three teams to make a 1.0 product, unbeknownst to the teams, and only ship from and keep the team that did the best.
These examples like the iTunes thing you list are them not caring, rather them not having the resources to get to it.
More precisely, I'm saying that Apple appears to suck at massively parallel use of their resources. For a company as big as they are, their cumulative output of high quality product isn't all that much. It seems they can barely keep macOS cobbled together now, let alone spin up groups tasked with shepherding individual components towards open source.
I think one of the biggest misunderstandings about Apple is the assumption that they have massive resources available to them, therefore they must have a wide bandwidth for competent development—be that in terms of vision, design, or code. The way I see it, Apple seems rarely able to focus on more than a few things at once. They have never been able to maintain high standards across the full breadth of their product stack.
MacOS tends to get jankier and cruftier with every release. At this point it's akin to a very pretty rug that has had so much mess swept under it that it's impossible for it to lie flat.
If you've ever dealt with the back end of Apple Music (née iTunes Music Store) you'd know that it's held together with a lot of crummy, barely-maintained software that falls apart under the most trivial of circumstances. For example, their iTunes Music Producer software can't even rip two-CD sets without causing file name conflicts in the XML. This bug has not been fixed for over a decade.