I worked at Apple as a developer. I just went to another company just like everyone else does.

I know lots of people who have spent their entire careers there because the work is challenging and interesting. I also know teams that handle anonymous backend infrastructure e.g. AppleID or ADC where there was higher turnover.

No different to any other company.

Honestly all the great apple devs from the early 2ks have either moved into consulting or entrepreneurial activity or, more likely and worryingly, they've been promoted into management roles at apple where they're managing a team of engineers not quite as good as they were. You see this everywhere, at every company. That's my guess.

Are you seriously arguing that engineers were better “back in the day” and engineers now are not as good? Surely I must be misunderstanding you.

The talent pool of engineers capable of propelling a company technologically forward the way Apple was "back in the day" is by definition very shallow. He's not saying engineers are better, it's just a selection bias.

Dunno, but it would make sense. Huge apple success post iPhone + exploding tech scene provide a ton of opportunity/temptation to leave.

Anecdotally, Chris Lattner is a high-profile recent departure. :-)