Why are there separate gear sets, skills and mechanics for PvP and PvE? Why cannot it be one set for everything: sometimes you kick, sometimes you get kicked?
Why there is a separation between PvP and PvE in WoW? Sure, I understand that ganking is prominent if there is no such thing, but... still, why they have been made separate?
The other thing is that there seldom are any punishment for ganking or player killing. In real world you commit a homicide you get cops after you. You kill someone in the less civilized parts of the world and you get the victims family, clan, neighbours after you. You know you will be avenged. In MMO's with PvP... seldom, if not rarely at best.
The bottom line is...
What drives players kill other player characters even when there is no challenge involved (less experienced, less geared, lower level)?