I'm not sure if you remember but this was exactly the route that Windows 8 took and it was a giant failure. There was a "tablet" mode and a "Windows" mode with

I'm not sure if you remember but this was exactly the route that Windows 8 took and it was a giant failure. There was a "tablet" mode and a "Windows" mode with a start button. App developers couldn't figure out which one they wanted to optimize for and ended up making half-assed versions of their apps for both sides of the OS and end users were confused about which mode they needed to be in for which apps and how they could multitask to switch between them. Power users didn't really have many issues as the paradigm isn't all that complex but, in daily usage, it was a big mess and it never made any headway. It was the first thing they got rid of in the first Windows 8 Service Pack. Apple knew that and saw it and I prefer their cautious approach and would be fully against what you're suggesting unless there are some major UI changes.