I think revoking the license is the only tool in the toolbox that can force ChessBase to release their code. My understanding is that it is the action taken once it is determined that they are violating the terms of the agreement. It's the basis of the legal battle.

If you can't revoke the license when the terms are violated, you haven't got much of a license, have you?

Isn’t that what’s been attempted for years unsuccessfully? From my limited understanding ChessBase has been warned and informed they’re breaking the license for years.

This is explicitly included in the GPL as a punishment that can be executed against those that continually refuse to correctly follow the rules.

If someone doesn't want to follow the rules the answer isn't to force them to play and then wait for them to break them again. At somepoint you just have to say no.

You're somewhat confused. They can absolutely force ChessBase to 'play along' since it has no right whatsoever to distribute someone else's copyrighted code without a license.

non-exclusive digital property does not play well with markets based on exclusive property. this is a problem in principle.

therefore I see two broad directions:

1. someone finds a way to have a market-like entity which is compatible with non-exclusive goods (like digital goods are). I am not sure what this could be... I don't think anybody is.

2. we give up the advantages of non-digital exclusivity and make every instance of digital information "unique" (say, like NFTs) and then police out whoever has copies of such unique-exclusive. in short: artificially enforced digital-exclusivity for everybody; I guess kinda like DRM.

I think there's a broad social (ideological) motion pushing along the digital-exclusivity path (number 2 above) towards a vision which somehow allows some small specialist group to keep all the advantages brought about by digital-non-exclusivity. I say this because of the way corporations act around open source ("well maybe a little bit") and free software ("ugh, icky") and because of recent trends in common views of open source.

They kind of doing that. Publishing the code would allow them to get their license back I think.