I don't think iontruo2 was concerned with any of the differences (and neither am I)-- I suspect his focus was on the important similarities. At the end of the day your complaints become moot; given that we do indeed learn to write with some sort of stylius, and continue that until death, it only stands to reason that any hurdles in the way of achieving that on tablets are simply opportunities looking for solution.

Which just goes to show it CAN be done. All it requires is commitment. And even then, your example still does not preclude a UI approach that uses context to switch cleanly and transparently from stylus input mode to anything else we can imagine.