It used to be but not anymore. The iPhone is Apple's most important product and the majority of iPhone users aren't interested in the Mac.
The majority of Mac users are producers, creating content for the iPhone users. If they kill Mac then their iPhone cash cow will dwindle as they will no longer have content.
That's not true at all, and sounds like Mac user elitism that everyone hates.
It is true, that many iPhone users aren't interested in mac and some not interested in any kind of desktop/laptop device at all. The same true vice-versa - I have a mac* and not interested in iPhone and plenty of my colleges are the same.
*: One because compliance is easier than on Linux and another one because I need to develop for mac and iOS.
If you are making stuff for iPhones, you essentially have to have a Mac because XCode to create iPhone apps requires a Mac to run. I meant the majory of app creators are Mac users. So if they kill the Mac workflow then they will castrate the cash cow that is the iPhone.
I know there are alternative workflows you could make by using something that can cross compile to iPhone and using a Windows/Linux system, then renting a Mac device via a cloud service like AWS, but I would be surprised if it made up a significant amount of development.
If the Mac disappeared today in a puff of smoke, would that result in less iPhones sold, a less prestigious brand, or maybe an improvement?
An additional argument is that companies rarely have one major product. Apple is big enough to execute well on several synergistic fronts.
$30b is an awesome business all on its own, and compliments, not detracts from, the iPhone brand.
Apple should be able to execute in multiple domains with a high degree of quality all at once.
> $30b is an awesome business all on its own, and compliments, not detracts from, the iPhone brand.