Why doesn't smart phones now a day come with a stylus (small pen) ? You can interact much faster and with better precision using a pen, compared to using your f

Why doesn't smart phones now a day come with a stylus (small pen) ? You can interact much faster and with better precision using a pen, compared to using your fingers. Apps are designed to be used with clumsy fingers, with dumbed down and over simplified user interfaces, there is so much potential left out. I would like something like Windows 8, yeh you are probably rolling your eyes now, but they where on to something, eg running the same os on a phone and pc, and being able to quickly switch modes. My hope is that Linux one day will be able to run on virtually any system "out of the box" turning smart phones into small personal computers instead of smart phones.