You didn't explain anything about why they're the problem. So they make more money off used games than new and concentrate on it and have grown their business? The last I knew, that was free enterprise at work and there was nothing wrong with it.
All that your explanation provided is a possible partial explanation of why the industry is now paying more attention to used game sales as GameStop's business has grown and they've seen the money they're raking in (And incorrectly assume that every dollar spent on a used game is a dollar they're owed and didn't get). But you've failed to explain why their focus on used games is inherently wrong and why they're to be blamed for the situation.
Saying it should be a specific way doesn't make it so. That's not an explanation in the slightest.
The situation isn't any different in the world of videogames. Microtransactions, single use unlock codes such as online passes, subscription fees, ingame advertising revenue, and I'm sure other ways have made it increasingly possible for console manufacturers, developers, and publishers to make money after the initial sale of a game. That applies to original buyers and those that bought the game second hand, just like the parts replacement business for automobile manufacturers.