The reselling of digital products simply makes no sense.
Reselling, trading, and all other forms of swapping, only work because, when those things were created, all products they dealt with were physical, and thus could decay, and wear down, making it to where people HAD to eventually go out and buy new versions of the product, and thus prevent infinite trading, which would destroy any and all product makers because they wouldn't be able to sell enough of their product in order to recoup initial expenses, and make a profit to spend on making more products.
Digital products however don't wear down, unless you slap some artificial decay mechanism on them, like digital books did, which people screamed bloody murder about being unfair, despite it being TOTALLY fair. So trading digital products simply isn't feasible because it would mean only one person had to buy a product ever, and then they could just trade forever with other people, and no company can survive like that.
Not being able to trade digital products is a result of them NOT being physical products, and not having the same flaws as physical products, which means they shouldn't be treated the same. You get a product that lasts forever, but at the same time can't be resold, that's the trade off, that's the balancing factor that makes digital products on the same level of fairness as physical products.