There's also been more than one case in which creators have lost their stuff due to a computer failure and had no backups. They've had to appeal to anyone who might have their items to send them copies. I can understand that at the time they release something, people may not want to just make it public domain. They may not be thinking about the future, including the fact that they might die in a few years, which has happened as well.

The repository idea has been discussed on occasion for a long time. IMO, it's the best idea since it would give creators some control over the circumstances under which their creations would be released - if I die, if I loose interest etc. It needs to be organized and promoted though by a reputable entity that will hopefully be around long term and can be relied on not to try to sell the items, take credit for creating them etc. - preferably, it would be part of the community rather than a generic 3D site. That pretty much means Daz or Renderosity though I'm sure others might qualify as well. Daz is more into their own stuff so here seems to me to be the best choice. It would take some work to figure out the specific mechanisms, but I think it could work and it would certainly be a great service to the community.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken