OS release schedules
Can you imagine if it were Apple delaying a software release. What would the press say if Apple admitted it took shortcuts with its OS to keep up with Google and now they couldn’t release it? The press would have a field day with that story.
You're right. Apple would never release, say, an OS with multitasking in it for only their new phone platform, and not make it available for their tablets for months. They'd get ROASTED.