> 1. Old bugs are not fixed.

If Apple would open source some of its OS apps, this would probably be a non-issue, I could see people putting in bugfix PRs the second Apple chooses to open source their core apps.

I don't see them doing this any time soon sadly, but it would make macOS much more stable, and probably secure.

The more I have thought about my views on Open Source vs Commercial software, I strongly feel that infrastructure code (an OS) should be more open source, I dont see Microsoft or Apple open sourcing any time soon, but it would make a world of a difference, imagine a world where Windows XP had been open sourced, and the community took it fully over and maintained its security, you'd have a drastically better version of Windows without all the fluff, or heck even Windows 7, which some argue was the last good version of Windows as well.

I wish ReactOS was drastically more usable.

Of the two, there's a lot clearer line to Apple open sourcing some of its core desktop apps, given market share (~16%?) and lack of internal resource prioritization (iOSiOSiOS).

The best time to do so would have been ~2010, after iTunes revenue provided a clear monetizable carve-out.

The second best time would be today.

The number of people saying 'I love the hardware you sell me, but am switching platforms because your software is trash' should be a flare that even Tim Cook can notice.

And anything that moves MacOS closer to OSS should be welcomed by Apple -- it's their easiest (and most affordable) path to competing with Microsoft (Azure) on desktop.

Mail.app alone had enough issues and missing features to sustain an entire cottage industry, and would be one app I would certainly like to contribute to. But it shall never come to pass.