DKs were put in at the same time as the honor system to address so many people killing NPCs that were needed, but by doing so it was a bit more insurance than we really needed since most PvP was then moved to the Battlegrounds. I'm not saying we don't want PvP to still continue in the Battlegrounds because we definitely do, and we want it to occur in the Arenas and in the World via the World PvP options that are implemented and being implemented.

We don't want to kill city raids but we also don't want to have cities under siege 24/7. That's why you don't see the major city leaders dropping any sort of loot to make them a prime target for people trying to equip their characters. (I still would like to see some epic cheese though. mmm mmm)

There is a very delicate balance that we are trying to create here and it's not as simple as doing one thing only. It's like working a cryptex (ala Davinci Code). Getting everything just right is what everyone strives for. In this case though the code consists of what a variety of people want and figuring out exactly what combination is going to work best to make the most people happy.

Via WoW Forums