I remember buying used Nes games. I remember game magazines being filled with ads from different companies that bought and sold used games. And somehow the game industry survived.
its a matter of convience. diablo 3 for example when you make the commoditization aspect too convenient (dialo 3 auction house) it circumvents all the aspects which had previously worked fine.
in the same way back when we had those magazines and such and even funcoland made used games it was still a hassle to deal with and it was a small percent of the game industry, plus small used sales like this had much more favarable and FAIR pricing and most of the money went right back into the games market. However gamestop saw this potential and greedily monetized the hell out of it. instead of the money going from gamers to gamers it just goes straight to corporate so basically stock holders, hedge funds, corporate bonuses typically not even gamers.
the problem isnt used games per say its gamestop. i fully support small scale used game sales from person to person, mom/pop shops, even full retail purchase because developers/publishers make money. it removes a needless middleman and its essentially gamers helping gamers.