I've not worked at Apple before, but it wouldn't surprise me that a lot of these quality issues come from their supposed culture of secrecy and compartmentalization where no one knows what anyone else is doing for the most part. This makes it hard to test things end-to-end as an integrated whole before things get released.

At my employer, our culture is almost the polar opposite -- everything is open unless there's a need not to. Every employee dogfoods the latest builds of our apps/website/hardware before it goes out to the public, and culturally, internal feedback is encouraged. This is invaluable QA signal (in addition to automated testing and traditional manual testing) and a key part of why we can release as fast as we can.