For a 'normal society' to function there has to be some form of 'limits and control'.
If you just stand back and say I'm not going to be a savage (I'm like too above that) while savage's are killing you off - you are going to be killed sooner than later.
The concept of the Death Penalty and other forms of punishment didn't just appear out of thin air - it became a necessity for society to function in a peaceful way.
Read HG Wells' Time Traveller.. it explains the pacifist scenario very aptly.
