Not my DMs. they would always target the mages and archers and other backline unless we used an assortment of manuevers to prevent them.
Play an MMO without an aggro system - you'll see how my past DMs ran the game. Every mob tries to 'geek the mage' and as a warrior, you spend your energy trying to prevent this with blocks, trips, knockbacks, or even just plain forming a football like defensive line (remember, WoW lets you ghost walk through other bodies, but many MMOs do not - in both Guild Wars and Everquest if you stand in someone's way they can't go through).
As for how the new DnD mechanics force aggro... just try to ignore it and see how long your mobs last. And note that as the toons level up, they'll get encounter and daily powers that are even more effective at forcing aggro.