I personally see the banning of used games as a bad business move in many aspects of the industry. Not everyone can or wants to risk $20, $30, or even $50 on a game. If only a few people buy the first game of a new series, you are limiting future sales to those and maybe a couple others. But say if a game is bought used, and the game is passed around between friends, that is free publicity that can grow future sales of that game and its sequels should they be released.
Such moves would also harm the retail market, namely brick and mortar mom and pop shops that buy and sell games and other pieces of electronic media (among other things). Such places create jobs in their community, and if those places loose a chunk of their revenue, cuts would have to be made in the name of jobs.