To me, this is among the most important source of value in a video game. Why? It makes buying a game non-permanent.Why is this important? It means that when you buy a game, you are essentially actually having in on really long term rent. Most stores have a return policy - if you can finish the game in 7 days, or don't like it - guess what? You can return it.
I can never finish games in 7 days, unless it was a short FPS. I'm still playing Disgaea 3 up to now. RPGs and realistic racing sims can last you forever - well, unless you get bored.
Game companies don't see it this way. They think that by locking you in once you've bought it, they can make more money. If your game is good, this is never a problem. Why? Ever see many copies of Final Fantasy XII second hand in a store? (Well, I don't know about other countries, but in Australia, good luck finding a 2nd hand copy of a good game.) Even if you see them - consider how many got sold - and then think about how many are being sold now.
If your games are awesome, most people will keep them. Companies who make good games should never worry about this. Of course, they'll whine about the (maybe) millions of dollars they'd supposedly make.
Bad games however pile up VERY VERY quickly on preowned shelves. Notice how there's somehow like tons of copies of a certain game on the preowned shelf? These are the people who would be losing money over resales. Why? Their games are getting recycled through the market at a super high rate.
This is good for us. This gives game companies a massive incentive to make good games - and a punishment for churning out bad ones.
I, for one, make it a rule to only buy games I intend to keep. But I have friends who buy games to try. They're more adventurous (and probably more loaded) than me. Would companies really earn more from locking them into their purchases?
They'd be punishing faithful buyers for their bad purchases. I can imagine people beginning to question their purchases a lot more for less reputable games. I think this is going to hurt the game industry in general - unless they give us something in return. And what is that something? Cheaper games.
Games with less resale value (or maybe even none) sells for less. A look on eBay easily confirms this. The market knows resale value counts towards the value of a video game - and it will be enforced. A lot of people saying they don't like recycling of games should take this into account - not many people will pay the same price they're paying now for a game that has no resale value - and you run the risk of your game doing even worse than it would otherwise (since people have to be more careful buying games they can't resell).
Would you make more money selling less copies that cycle through the market - or more copies at cheaper prices that don't? It's something to ponder and a topic to research - not something I can answer. But I love my physical copies. :D