The logic just doesn’t flow. If the problem with illegally streaming content is that the creators don’t get paid for my consumption of their product, then buying a used copy is just as bad, because I’m still consuming the product without the creators being compensated. You can say it’s different because I’m using physical media that can’t be copied rather than using a copy of a digital file, but the end result remains the same: I consume the media, the creators don’t get paid. You can say it’s different because the physical media only allows one person to consume it, but… The original owner already did. I suppose they can’t rewatch it after they sell the disc to me, but they have definitely already consumed it.

It also brings up a complicated question: what if the original buyer of that disc rips the disc onto their computer before selling it to me? Is that immoral? I mean, they already watched the show. They might not have a legal right to keep that digital copy of the contents of that disc, but it seems weird to me to suggest that it’s immoral to keep a copy of a show you’ve already seen.

Finally, if buying a used copy is fine because the original owner of that copy already paid for it, then my illegal consumption doesn’t matter at all–the person who bought the disc was going to buy the disc anyway. They already paid for it, regardless of whether I would come and buy it from them in the future.