The "deserve" argument is beside the point. The point is that used games affect the revenue that gets returned to creators and investors, whether they deserve it or have a legal right to it or whatever other irrelevant argument is bought up. The more people opting for used over new, the greater the amount of revenue that ends up in pockets other than those of the creators and investors. And that affects what those creators and investors create and invest in. And they will increasingly create and invest in stuff that is less vulnerable to the effect used games: digital platforms with DRM, DLC, consumables, non-retail and non-console games, etc. This is already happening, and it will happen to a greater extent next generation.
It is interesting, though, to see people claiming that creators have no right to used game revenues, and yet they still expect them to provide game support out of their own pocket to people who buy used games. Just another instance of used game advocates' twisted idea of "fairness" and unwillingness to look at the full picture, only the parts that benefit them.
Used games do reproduce, in an economic sense. One new game traded in can spawn numerous used game sales.
So you've never bought a digital game or a piece of DLC?
Used games don't necessarily save you money. I get digital stuff "new" far cheaper than you get used games.