Well,
As I said, a LONG time ago, and I mean years.
Pick anyone here almost and say, well guys, we have this large 10" screen, with a 2000x1500 is screen rez, amazing, size and pixel density.
It now up to you to design the most amazing user interface for it.
How much do you think you'd have gotten paid, if after a few years of work, you emerged and said, ok, well we have a background image, and put some large icons on it.
Whilst I'm not saying Msoft have things perfect, I do agree that, there is a bit plus to having things you wish to see on the screen instantly. Without needing to pen apps to check things.
Split screen, or windows, but there is always the 4:3 problem, which is not really ideal for cutting in half in the 1st place.
I guess the inevitable is, what you suggest.
If it's fast enough to run OSX then it should be an option, perhaps it will do 2 modes?
The problem is...... If you are going out for the day and might need your laptop, then why carry an iPad also.
Or just carry an iPad and worry you may be limiting yourself too much.
There really is little need for a Tablet and a Laptop to be two devices.
They are the same thing, in reality, only difference is one has a bolted on keyboard, the other has a optional/removable keyboard, and one is faster.
It's natural for, eventually there to be just the 1 product.
It could not happen in the past due to power of the device, but every year the argument will get harder and harder