Characterizing iOS 11 as a mess is a gross exaggeration. If you told 99% of iPhone user's their phone was a mess, they wouldn't know what you were talking about. I would say Android version fragmentation is a significantly larger mess than anything Apple has ever done.

> You just need to look at the frequency of iOS 11 point releases to see what a mess they've created

Another interpretation is that they care more about software quality, and are fixing things that would be left broken by other manufacturers.

More Frequent updates doesn’t neccesaraly mean more bugs. It mostly means that they can patch the OS much more quickly and easily.

Also some of these updates are feature updates and many of the updates on iOS correspond to updates to play services as much as they aren’t updates to the core OS.