That's not quite the case any more--those teams have gotten larger over the years (from what I've heard). That said, building the right features/product is often a lot about focus and focus is much easier to obtain with a smaller team. Apple's are definitely smaller than Microsoft's but Apple, imo, also tends to hire developers who are more considerate of or passionate of customers than Microsoft's more tech-oriented engineers.
I worked at Apple for 6 years. Believe me, the teams are still very, very small and focused. If you have a small team, you don't need to worry so much about feature creep: you don't have time to work on the less vital stuff
Yeah, should have been clearer--I do think the dev teams at Apple for the same product tend to be smaller than the equivalent team in Microsoft (just, specifically, I know that some of the teams you mentioned have grown). The small teams at Apple probably enforce all sorts of interesting functions such as not chasing half-baked features and leveraging more platform/shared code rather than Microsoft's often NIH approach to things.
Apple lets go of a number of things that Microsoft chases such as a religious concern for backwards compatibility, globalized features (not just localization but geo-specific features), and deep product extensibility with corresponding dev support. No judgment on those decisions but I'd argue that the size of MS teams isn't directly reflected in the product or features most folks consider as users of Microsoft's products and I wouldn't criticize MS based on those team sizes (as the author of this article does). Instead, I'd criticize the PMs or other managers inability to bring focus to those teams to clearly tackle the right problems at the right level of investment at the right time. It takes a lot of discipline to say "no."
There are about 20k, up from 10k when I started there 6 years ago. But I think 5k-8k of them work at the retail stores around the world.
Then take into account all the people who do QA, all the management, marketing, business, finance, and other teams.
And you're actually left with a pretty lean engineering force. Apple engineers more stuff in house than a typical company like Dell, so that plays into the head count as well
I intern'd at Apple and I would say that Apple's engineering talent is a level below Microsoft and Google. Apple combines good (but not incredible) engineering with the best product management (manager maybe...) on the planet. Microsoft and Google have much strong engineering teams but their much weaker on the PM side.
Final Cut Pro was around 15, which is still incredibly small given how big our application was.