I fully agree with the author on that text editing is nothing but cumbersome.
But instead of modifying and (hopefully) improving on what we have now, I would actually prefer an entirely different solution; one that disables any touch input on textboxes.
In place of touch, I'd prefer a new keyboard screen containing a joystick to move the text cursor with.
On the opposite side of the keyboard, you could have all the context buttons, together with a 'select' button which can be held while moving the joystick to make a selection.
Add a toggle button to the existing keyboard to switch from and to these new input options and you're all set.
Whether this solution is intuitive enough for the average mobile user is up for discussion.
In place of touch, I'd prefer a new keyboard screen containing a joystick to move the text cursor with. On the opposite side of the keyboard, you could have all the context buttons, together with a 'select' button which can be held while moving the joystick to make a selection. Add a toggle button to the existing keyboard to switch from and to these new input options and you're all set.
Whether this solution is intuitive enough for the average mobile user is up for discussion.