Nobody ever needs an excuse to kill evil: conversely, evil needs no excuse to kill you.

But there's a difference between attacking a brutal thug who is quite obviously a threat to you, and attacking that innocent girl whose asking you if you want to buy some flowers. If your neutral characters don't differentiate between the two, then there's a serious problem and its probably cause you're rping someone evil.

Neutrals are way too free as it is: it should be terrible rp for svirfs to kill other svirfs, unless they have a really really strong rp reason for it (e.g. other person is within an opposing cabal). As it is, anyone neutral is able to kill whoever he wants whenever he wants for gear, and they've got a lot of freedom in choosing which PCs to attack as well.

A role that goes "I like killing things but I'm neutral so I kill all things equally" should not allow you to get away with behavior that really belongs to evils~