I love how people pretend that the video game industry is the only industry that concerns itself with maximizing profit by curbing the second hand market. News flash: Every industry that has the capability of curbing the second hand market, has recently made strides to make that a reality. We've seen this within media related industries (video games, movies and music) with a huge push for the transition away from retail towards digital. We've seen it with publishing, with the push for Tablets and E-Ink Readers. The text book market has implemented rapid edition changes, and online components to their text books to hinder their second hand worth.
And it's disingenuous to suggest that used cars and used games are at all similar. The games industry is the only industry where there are major brick and mortar retail stores (many of which built empires on the backs of used games) that dedicate major store space to used products whose brand new counterparts are only days or weeks old. Cars are used for an expanded amount of time, and degrade (physically and in value) over the course of its usage, and new ones eventually need to be purchased at some point. Games can be played for the few hours it takes, and once you're done with it, can be sold to someone else (days to weeks later) and that person will have EXACTLY THE SAME experience as you did. There's little advantage to buying a new game in that scenario. And unlike cars, publishers/developers don't have the benefit of having retail dealerships to sell their own used products. It's a unique issue that cannot be directly compared to any other industry's situation.
It's pretty clear that the current direction of the industry is unsustainable, but honestly, outside of practices that are considered anti-consumer, what can the industry do to fix the mess it's in? It's obviously not healthy considering the rate at which developers are closing up shop. And this is where the problem's situated. The PC, mobile and browser gaming industry have solved their problem by shifting to the digital space, alongside setting some games at a lower price point.
Console games have already tried to lower the price of entry through Arcade/PSN style games, but it's pretty much impossible to lower the cost of development for AAA titles due to market demands. While their are certainly successes within lesser budgeted circles, for the most part, it's your mainstream blockbusters that are growing and expanding the industry into the mega force it is today. Is it unsustainable in its current form? Absolutely, but unless market tastes shift dramatically or the industry collectively lowers the scope of the games they're developing, then the current path of big budget AAA development is unlikely to stop.
The other course of action is to mitigate used games by shifting consoles to the digital space like PC, mobile and browser developers have done, but anytime such an idea is hinted at, hardcore consumers lose their damn minds. Outside of lowering the cost of development or shifting the industry into the online digital space, pretty much everything the industry could do to protect itself is considered anti-consumer. Downloadable content, DRM, a shift away from single player to online play, always online consoles, etc. There's honestly not much the industry can do. A lot of people say to "make games that consumers want to play," but there are several developers that have folded this generation despite making quality games. People will also say to scale back the scope of development and lower costs, but consumers clearly want the opposite considering the games that they're ultimately supporting.