if they did that, they'd have left the games as is. I like the idea of a continuing game, as they complete more crap for me to do, I am happy to get it and play it. The game is excellent, some of the DLC is not so great, but to my mind, they are just starting to crank new content out. Soon it will be some great stuff with the mod-community involved. Soon, we will be seeing epic stuff based upon the DLC addons to the main game ... so keep that stuff coming. Duncan's Sword, the King's Armor? Looking for the details behind the betrayal? All cool plot points.
If you don't like it, don't get it, but don't tell me it sucks, it has the ability to keep this game fresh for far longer than any DL and forget game we have been playing for the last 20 years. Add to that, if this works correctly, it will become the new market, this will lead to DLC for all games, be they FPS, RPG or RTS.