People keep asking, so here is my reasoning on the subject:
The central reason for removing stats is that it divides the player base and requires much more content to have a full game. With no stats, any player has the option to use any of the weapons and items in the game:
Sword
Crossbow
Throwing Knife
Magic
But if we divide the players up into different classes, then each class can only effectively use one or two of those items. That means that there would have to be many many more items in order for each player to have the same number of options as they would without stats. You end up creating a seperate game for each player class. That is not an effective use of content for a game of this scale.