I find it interesting that people seem to disparage the "main character" role, but without it their "secondary characters" have no real meaning.
I think it's vastly more difficult to be the MC because it takes a lot more effort and you have to entertain others more than yourself. It's the big D to the little s.
But is there even a "main" or "secondary" character in roleplay? If we go on the idea that RP is simply us acting out the world Blizzard has presented us with as if we were actual people in that world... then it's no different than asking about who the "main character" of real life is... which would be silly.