Come on. Sometimes you just play WoW to kill things. Whether it's PvP or PvE, sometimes, it's not about getting better gear, or grinding points, or anything other than enjoying seeing things fall down. It's one of the reasons I enjoy leveling new alts - learning how to make things fall down in a whole new way. I enjoy other things, sure - I like exploring, I enjoy transmog quite a bit - but I can run a dungeon over and over again just to enjoy cutting loose and making things be dead. I enjoy watching a team come together to make a raid boss dead, with all the execution needed. And I enjoy just killing hapless mobs. I enjoy running AV or Arathi Basin or even occasional world PvP.
In short, sometimes, I just play WoW to make things be dead. How about you?