Depends what you mean by "change the world". If changing consensus views counts, which I would include in the definition, then obviously people such as the founder of charities such as Reprieve and Kids Company have changed the world.
i think this is generally true, but not specifically.
Well now, let me think here. Hmmmm. There has been bloodshed since the beginning of time as far as I can recall from any study of history I indulged in. If it had resulted in any real or lasting change, that would be apparent already by the end of that bloodshed. Apparently bloodshed just doesn't work, which is why human beings keep on doing it. Anything that goes against the principle of survival of the fittest, of the continuing our species, that is precisely what the human creature will do. So as you can see the answer is really painfully obvious.
