If only apple had enough money to hire more engineers
Sadly it is not that easy. No matter if they have a Computer Science degree, or even if they were a Doctor of Computer Science (though for a project like this, that wouldn't be "special" to have) and had 5+ years of industry experience you can't just hire someone off the street and the next day they can jump right into this big project that is entering crunch mode and whip off code like that
1: You interview them, and interview a lot of people. That can be a long process. I'll just skip it and pretend it was instant.
2: You agree to hire them and officially offer the job. They accept.
3: What if they already were a place and needed to give at least 2 weeks to a months notice? Well you wait longer.
4: Ok, now let's say only after a week of offering them the job they start. What now? Start work? Not quite
5: Get familiar with the code base/get setup. Every single development company has their own way of doing this. The new coder has to get familiar with their technology, their coding style, and more. Matter of fact they are still more than likely reading and studying the manual that all coders for the company most follow. This follows coding styles and guidlines to make it easier.
6: Familiar with the project. How is the design of the project? What are they expecting? Where are they currently at, working on, needing done?
I can go on on. More than likely they haven't even started any "real" coding work for the project. They haven't put them on the biggest task yet. They are getting used to the coding style, guidelines and the technology being used on the project. Even their internal libraries they have to learn.
You expect someone off the street to just jump right in and be able to implement features and fix bugs without any prior experience of the code base? Nope.
You move from within. They have experience with the style, guidelines, internal code libraries, technology and more. They know what is expected. Their is virtually zero setup time.
Every development company does this. Don't act like it's only Apple and they are being greedy or something and not hiring more people. If Apple was just hiring people left and right off the street I'd more worried about this company actually. Hiring people this fast? Needs spots filled up that fast? Not a good sign when a company is doing that and it usually shows in the finished product.
Their is a lot more to software development than just a coder typing code all day. Matter of fact a coder might not write very many lines of code all day and it could still be a productive day at the office. Maybe they figured out an internal code design problem? Maybe they figured out a memory leaking bug? Maybe they figured out this crazy bug that was crashing all their systems, who knows. Coder being productive isn't measured about how many lines or how few lines of code they write.