First sale doctrine applied because the license is tied to the physical media.

If you were to make a copy of your DVD and then sell the physical media on to someone else- that's always been considered piracy In the eyes of the law.

I'm not making value statements on what's right and wrong here; I just want to clear up some of the misconceptions around how we currently talk about it.

My personal belief is that digital licenses should be transferrable just like physical ones, and that any company that wants to offer DRM such that a license key becomes invalid shall allow a license key to be transferred to another user without restriction.

On a deeper level, the US needs a rethink on the laws surrounding software and copyright, balancing two truths: digital content creators need to make money; and buying a license or right to use any form of digital media IS ownership, and should come with all the same protections as, e.g., buying a physical book.