Truth. Arena's are pretty much the only reason I played WoW for a very long time. I honestly haven't even logged into SWTOR in over a week, and I don't feel like I'm missing a thing, like I would if I took a week break from WoW.(Keep in mind, for the time period in which I am talking about, the only thing I did in WoW was arenas)
Arenas add a microscope we don't need.
But they add a fun factor that players like me need.