Joel Spolsky's point: They did it by making the single worst strategic mistake that any software company can make: They decided to rewrite the code from scratch.
Statements like that, while powerful are dangerous as they turn into baseball bats for people to hit each other with.
And they become an excuse for ignoring things and becoming an absolutist religious zealot.
There are legitimate cases where rewriting the code from scratch can be the single BEST strategic decision.
(And of course, vice versa)
If I have strong rational reasons to believe that a rewrite is warranted quoting Joel Spolsky or anyone else is not going to change my mind.
I will quote you a lot from this time on. It is such a true and widely applicable judgement.
I love that analogy.
I see it again and again with so many of the "classics" - phrases like "premature optimization is the root of all evil" and "adding manpower to a late software project only makes it later". Sure, these statements are right more often than not, but the zealousness with which they are often applied leads to an enormous amount of mistakes.
There ARE cases in which optimizations aren't premature. System architecture is all about designing a system for optimal performance in some area or another. And in some cases, bringing in more people to a late project can speed things up.
The problem really is that the new Disk Utility is a minimal viable product, rather than an app that can actually do everything the diskutil command line utility can do.
And then you have terrible bugs like this, which is presumably a non-security engineer writing a bit of UI code that they shouldn't be. I doubt this bug actually came from the APFS encryption itself.