I agree, but I'm pointing out why UI changes happen. Apple could certainly do UI changes as part of a cleanup release though. Basically start with getting back to consistency pointed out in the article.
But, having worked with users I've seen first hand out tons of internal improvements are ignored while one small UI change makes 'everything seem new'.
Don't you feel that the circumstances are similar though? There was a pressure (expectation and competition) for new features. There were rapid changes in the UI and UX. But also bugs. And IIRC Mac OS X upgrades were still paid-for.
It was a brave move to spend a major release without adding feature. And people were grateful for it, once it happened.
I'm all about them spending a major release bug fixing. I've been on their side with a much smaller project and see what users say though.
The analogy I use is that no one thinks about plumbing until it's not working. I could stand up and tell people we have the best plumbing ever, it's been improved, is less likely to break, etc... and as long as it works at a surface level it seems the vast majority of user don't care. We actually save little UI tweaks/fixes to point to when doing major behind the scenes upgrades so users 'see' we're doing something. It's silly, but /shrug.
But, having worked with users I've seen first hand out tons of internal improvements are ignored while one small UI change makes 'everything seem new'.