Sorry, I can't follow. On the one hand you say it's not in OSMs interest to argue in court there is no copyright on maps, on the other you say it's in their interest to give their copyright up?
If OSM cares about the share-alike part of their license, they have to successfully defend their copyright on the data. If OSM moves to open-but-not-share-alike, they no longer care if their copyright on the facts in their database is valid.
Thanks, I understand that better. I still think it's not a good argument; you seem to say that if they stopped caring about something there would be less trouble. That seems pure spinelessness.