If the concern is that the original publisher isn’t getting your money, and therefore the actual game makers aren’t getting paid, just look at it this way:
If something is USED, that means that someone, at some point in the past, bought it and the game makers did get paid. After that, the game owner is free to do what he/she wants with the cart/disc, short of illegal activities like piracy. Most retro games are not available for purchase anymore, so there’s no way the original game makers could make more money from it anyway.
Now, for retro games that are available for online purchase, I honestly can’t say if the original game makers are getting any of that money. Many of the development companies don’t exist anymore, or the programmers are working elsewhere. But, I would estimate that 80% of my collection was bought at retail during original release, and I don’t feel like I should have to buy them again to play them on newer consoles.