That is a fairly arbitrary restriction to impose on rights holders. You would have to justify that policy with a tangible public benefit. If I'm producing something for ephemeral entertainment purposes, I don't necessarily want to take on the cost of securing all rights for public performance of that product in perpetuity, and consumers are not necessarily willing to pay for it.
If it's not worth maintaining, then let the copyright go. Squatting on it seems to go against the purpose of copyright, and you get the worst of both worlds.
