As platforms evolve, old games become unplayable. Open sourcing them will help us preserve them for future generations.
A lot of old games have become unplayable on modern hardware and operating systems. I wrote an article about how making games open source will keep them playable far into the future.
I also discuss how making games open source could be beneficial to developers and companies.
Feedback and constructive criticism are most welcome, and in keeping with the open source spirit, I will give you credit if I make any edits based on your feedback.
I think a compromise could be that developers would have to open source their games if they drop support, like entire support not just maintenance mode, so that the community can maintain them from then on. They could still have some sort of licensing to ensure the code isn't used for something else or the product used for profit (this would not include something like maintenance cost for online titles so that community ran servers could be paid for).
And then the developer goes out of business or gets bought by 15 other companies, with the rights to the game being so muddy it's not even funny anymore.
It's unfeasible. Not one serious publisher will let their game be open source for fear of reverse engineering, copycat games, using engines that a company has worked on for years, etc.
Not only do the games need to be opensource, but their toolchains too. It would also be great if everything were stored in content-addressable storage. Then it wouldn't be necessary to track down stuff by follow URL paths to dead domains.
I hope that opensource game engines become more popular. It might just be a matter of time. Blender is now very popular and that's opensource.