To me, DLC is the autotune to the gaming world... it should have never been invented.
When new maps, characters, weapons and such were made, unless there was a substantial amount to warrant putting it all together and calling it an expansion, it was just given out for free. UT3's Titan Pack, episode IV of Doom, the insane amount of planes added to IL2 Sturmovik... things that developers made and just gave to players, even though it took quite a while to create or pull together. These days?
These days, you get charged for an extra spaceship type in Raiden IV, a small section of map in some railroad simulator, side quests that take maybe two hours to complete in an RPG or FPS... things that were free in patches just 10 years ago. Some might say it's to get back development costs, but considering that the games are priced to already do that (assuming the game's good and sells), it's just a money grab... plain and simple.
And of course, let's not forget that DLC stands a rather high chance of having been planned to be a part of the game in the beginning, but was held back for DLC purposes. Anyone remember Dragon Age: Origins and the little spot that Penny Arcade dug into its creators about? Yeah, that kind of thing. With DLC that comes out so close to launch day, there's no way in hell it's not a money grab... after you've already paid $50-$80+ for the game.
The fact that DLC is still around is ridiculous. The fact that companies keep trying to milk even more cash from gamers for things that should be free in a patch because it's so minimal, is a disgrace. And the fact there are people who snatch that DLC up so fast that it keeps the companies making it, is a disappointment.