I often buy pre-roasted beans so that they last longer in storage. This means I have to grind the beans.
I have a cheap spice grinder that does a great job at preparing the beans into ground coffee. It is easy to use, takes 5-15 seconds to process half a dozen cups worth of beans, and I have good control over how fine a powder to make the beans into. I'm pretty sure this is a similar story for almost everyone with an electric grinder.
I saw a friend using a hand grinder. It took far longer and from what I saw there was no discernable difference between hand ground coffee and machine ground coffee in terms of texture (if anything the texture was less consistent when hand ground).
Given this, why on earth would anyone want to hand grind?