The way it should be
You kill a mob. The mob has some sweet loot, but then another player runs up to my kill and steals my loot from the corpse! Since that player stole from me I should be able to attack them and have a PVP fight ensue.
Why?
Imagine 10 players in an area killing mobs. 9 of 10 players respect everyone's mob loot and they don't steal, but one player decides to go around and steal loot from other peoples kills.
What happens now?
1. The players can band together and attack the player thief.
2. All the players will remember the name of this thief and his reputation may cause him hardship back in town.
A few wonderful things manifested from the above encounter
* Player Community (players banding together for a common cause)
* A form of Dynamic Quest involving players only was established.
* Players get to know each other and may talk to each other over an exciting conflict.
THE POINT
Of every ESO beta video review I've seen, I haven't seen any interaction or communication amongst players due to a lack of conflict/interaction between players.