Great idea, and I seriously hope Apple listens to you. They push the MacBook 12 as a super tablet and the iPad Pro with keyboard as a mini laptop, so it only makes sense to converge the platforms.
What is the MAIN difference between the two interfaces? I’ve read somewhere (can’t find it in a timely manner) that it is the cursor. Everything else is more or less similar as far as the user is concerned. Yes, there are YUUUGGGEEE fundamental differences under the hood, but the average user doesn’t see these. No, it is the cursor that is different. For iOS, there is essentially no cursor. You point to the spot you wish to activate, etc. For MacOS, the cursor is always present, either in the form of the arrow or the text bar, and you move it to position with the mouse or trackpad.
I might be naive, but it seems to me that these two approaches aren’t incompatible. IF there is no pointing device connected (iOS mode) then there is no cursor, and one points with the finger. If there IS a device connected, voila, the cursor magically appears. Problem solved.
I’ll take a 5% cut when Apple buys your idea!