How exactly does this justify modern games just being disappeared by their publishers?

I loved Battleborn, but it wasn't long until it shut down, and when it did, everything went. Even the story campaign! It's gone! Forever!

That is NOT ok.

If you bought a game on CD back in the day, would you be ok with the copy just disintegrating the day some arbirary timed license expires?

Or if a piece of music you got as a digital file, had a fixed number of times it could be played, and then never again. Once all the copies in existence are used up, poof, gone forever, never to be heard by anyone ever again?

No, we can't require companies to support systems forever, but if they decide to stop running the private parts of the infrastructure, they shouldn't get to just press delete. It should be open-sourced. Even if the game itself remains proprietary, meaning you have to buy it, the infrastructure to actual play it doesn't have to.

And when games themselves stop being sold, they should, and could, legally become shareware. Instead we have dragons sitting on their piles like Nintendo, actively preventing access to content which cannot in any legal way be played, at all.

And it's happening faster and faster! OW1 is now gone forever, and games like Destiny straight up remove older content, meaning new players who want the full experience can eat shit and die.