Retailers already get a share on the sale of a new game. And then they can do a shitload of money on selling a used copy. I'm pretty sure overall, they can easily make more money off a copy of a game than the developpers themselves. And that only cost them some shelf space. You can easily see why this only can upset devs/pubs.
In the case of other goods, the majority of the sales do not involve a third party. Not to mention that in the case of videogames the used copy will stand next to the new one. You don't exactly see that with other goods. For cars, the only case when it happens is with licensed retailers, who either are owned by the manufacturer, or pay a license. In both cases the manufacturer gets money on used sales.
Then you have the time factor. VG are extremely short lived products, so the used market is more likely to have a huge impact on it. That's not the case with goods such as cars or houses.
Competition. For many reasons, a 15yo house or a 5yo car are not likely to directly compete with their "new" counterparts. First because in most cases they're different, and second because this kind of used goods come with potential problems and shortcomings. Except if the disc is scratched to death and the box is ruined, there is absolutely no advantage in buying new vs used for videogames.
Etc.
I'm not sure Jaffe wants to completely ban the used market, just that he thinks the way it works right now is totally unfair to the devs/pubs who spent a shitload of time to create a product, and retailers are making easy money out of it. And I think he's right.