In 1987, Alan kay said,
By the way, Sketchpad was the first system where it was discovered that the light pen was a very bad input device. The blood runs out of your hand in about 20 seconds, and leaves it numb. And in spite of that it’s been re-invented at least 90 times in the last 25 years.
Almost 50 years after Sketchpad, you can find a light pen at any computer store today. Today, these light pens are used to supplement more circulation-friendly input devices. Maybe that’s enough to solve the problems Sketchpad had.
Personally, I think the metaphor of a the pen is too blindingly strong. People love their pens, because they grew up with them. I don’t accept that they are the pinnacle of input. We can do better then copying a pointy stick filled with dye.
But I have my own biases and unique experiences. I am dysgraphic — I have trouble writing legibly by hand, and spelling. To me a pen is not something that feels good or puts me in the zone. It’s something that gets in the way of expressing my ideas. But fundamentally, isn’t every input device a barrier between your mind and the medium?