maybe it is a matter of taste but i am not particularity interested in being some support for a NPC Hero.
It is a MMO and not a single player RPG, true that but playing a single player RPG you also know that there are million others playing the same game, the same character even, it does not bother you.

If i watch a movie i also want the main character to be the hero of the story, i want to see what is going on, i want to be placed at the center of action. This is just another entertainment medium after all.

The argument that being the center of the story does not work because this is a MMO and not a single player game is lazy one at best. Just because there are thousands others it does not mean that the story has to be generic and that you can not be part of the action. Thats BS imo.