Yes, but I mean, what is so fun about it?
Depends on the player.
What I like is exploring the maps, creating a character and equip him so that he looks good ("stylish"), defeating low level mobs of the enemy fraction, PvP and so on. My goal was creating a level 80 Death Knight and I finished my goal in 4 1/2 week. My new goal is creating a Goblin race, Warrior class and leveling him up.
If you know how what works and when you know what you can do when, the game's really enjoyable.
Level 1 - 15 is a pain in the ass, for me, but afterwards its awesome. With the Battlegrounds and the Dungeons. Playing with different players, with friends. Making new friends bla bla bla.
It's the same like I would ask a FPS player why he plays a FPS game. Not everyone enjoys FPS games. I got bored of those kind of games.
I'm into RPG, RTS, Adventure, Jump and Run, Platformers and Racing games.