DLC is not needed to fight used game culture. Lasting game value and a willingness to decrease prices over time, rather than maintaining a strict $60 price point for 12 months after release, are needed to fight used game culture. What game publishers are complaining against is, basically, the forces of capitalism at work. To be frank, the fact that people sell games back to places like Gamestop is a sign that they feel the game isn't worth keeping around anymore. Now, look at some of the classic SNES games on Ebay:
Chrono Trigger - new in box, $1500
Final Fantasy 3/6 - in box, $50-200
Legend of Zelda: A Link to the Past - in box, $150
Contra 3 - in box, $200
Earthbound - without box, $100 and up
Hagane - in box, $750
Gradius III - in box, $50
Ogre Battle - without box, $50 and up
This is just a quick sample of the games that I remember off the top of my head. I'm certain there are others. Several of these are, far and away, valued higher than current-gen tech. A lot of this is collecter's value for unopened boxes, true, but look at what this says from a simple economic perspective:
The supply does not meet the demand.
Granted, there have been some moves to profit from this demand, releasing games like Chrono Trigger on the virtual console (not sure if others have received this treatment; I know that FF3/6 was also put out on a PS1 compilation disc with a few other classics), but lets take a look at some of the pre-owned game sales for more current games.
Halo: Combat Evolved - new in box, $12
Halo 2 - $12
Doom 3 - new in box, $40
Soul Calibur II - new in box, $10
Elder Scrolls III: Morrowind - new in box, $25
Max Payne - $12
Prince of Persia: Sands of Time - new in box, $20
Grant Theft Auto: San Andreas - new in box, $120
Silent Hill 2 - new in box, $110
It should be pretty clear that some of these things are not like the other.
Hopefully, this will highlight some of the discrepancy between supply and demand for some of these games. The price on a lot of modern games drops (through used games) mostly because the supply far outstrips the demand. Simply put, the fact that people do sell these games back to the store right after purchasing them - and at a steep personal loss, no less - should be significant of the fact that there is a feeling that not only are these games not worth the $60 they were first purchased for, but that they are worth closer to what these second-hand stores are offering to buy them back for. The fact that factory sealed copies of Silent Hill 2 are now selling for far more than they once were should signal to someone, somewhere, that the lasting value that these classic games hold makes them valuable.
The drop in price caused by used game sales isn't players being lazy, or corporations taking advantage of publishers. It's the natural market correction for a commodity that's being sold higher than it's actual value.