Maybe another reason why Apple spawned comparatively few startups might be that some of the areas of expertise for Apple and their employees are harder to do in startup-sized companies; namely hardware engineering and mass manufacturing innovation.
Apple does a lot of work in hardware and hardware manufacturing, both areas which are pretty capital-intensive and might not lead themselves as easily to the startup world.
Say, you are an Apple engineer working on the Ax chips for the next iPhone and have an idea for something great in CPU design, you cannot exactly rent a scalable 14nm chip fab from AWS to try to build it on your own and sell it market.
Apple does a lot of work in hardware and hardware manufacturing, both areas which are pretty capital-intensive and might not lead themselves as easily to the startup world.
Say, you are an Apple engineer working on the Ax chips for the next iPhone and have an idea for something great in CPU design, you cannot exactly rent a scalable 14nm chip fab from AWS to try to build it on your own and sell it market.