Earlier quoted context omitted.
It's not that we're particularly fragile, given the kind of physical trauma human beings can survive and recover from. It's that we have technologically engineered things that are destructive enough to get even past that threshold. Modern warfare in particular is insanely energetic in the most literal, physical way - when you measure the energy output of weapons in joules. Partly because we're just that good at makin…
Humans can render other humans unrecognizable with a rock. Brutal murder is low tech.
They are much less likely to.
We have instinctive repulsion to violence, especially extending it (e.g. if the rock does not kill at the first blow).
It is much easier to kill with a gun (and even then people need training to be willing to do it), and easier still to fire a missile at people you cannot even see.