Earlier quoted context omitted.
It is perfectly sensible to consider data and medium to be single product when you cannot update the software running on products that read it. It was not great sell to tell people to go get new player each time new codec was released. Or tell that these new movies do not work anymore. Have to remember that DVD was released in pre-always-connected world.
You could stick the codec on the DVD itself? They are relatively small programs.
https://www.cnet.com/tech/tech-industry/pentium-ii-release-d...
In other words, there was simply no way to ship affordable DVD players that would use a general purpose CPU for video decoding. It needed to be in hardware.