Fighting against others while leveling have always been something I liked very much - and no I'm not ganking - and I can get very angry when some coward attacks me while I'm fighting a quest mob, but at the same time I would never play without it. It puts the danger back in wow, which it have lacked for many years now.
Doing quests is so easy, and mobs got so low health that it is a joke.
The world (of warcraft) isn't dangerous and exciting without world pvp (imo)