I think your analogy is not really valid. For the purpose of moving from point A to point B, a car is better than a horse in most any way you can think of. For

I think your analogy is not really valid. For the purpose of moving from point A to point B, a car is better than a horse in most any way you can think of. For coding, editing text, illustrating, etc, an iPad with iOS does not hold a candle to a Macbook with OS X (or a PC with Windows or Linux, for that matter). Moving from horses to cars was disruptive, but it brought mostly advantages. Moving from OS X towards iOS does not bring such advantages in the general case.