The only exploit involved abusing your intelligence
What would be the point in having traders at all then if you can merely murder them and take their shit?
Part 2 is the inability to kill an NPC in a town and loot him which is the whole idea of the game. Full loot, full freedom to do whatever you want with off course the consequences that may follow
So in a game where THIS is allowed the problem is looting vendors?
You would almost never see a vendor with valuable stuff any more.