Dragon Age is more of an anthology like Elder Scrolls than a single story like Mass Effect. If that were the case, they would have created an overall plight for the entire series to stop. Dragon Age 2 wouldn't be half the game it is without the lore of the Dragon Age universe. Had it been a new IP, the game wouldn't be out for another year or two, and then what would be the point? The game was rushed, yes, but your suggestion removes all possibility for innovation within a series that never promised to be what people have been expected due to the high bar Mass Effect 2 set.