So corporations get their own copyrights? Then they can just create a new subsidiary to hold each work. Maybe transfer employees to it while producing it, and then move everyone out when it's done. It'd be annoying having to manage all of these subsidiary corporations, but I'm sure they'd be up to the challenge.
Also, if copyright can be transferred, then there'd be 2.1 billion lifetime copyrights available. A substantial portion of that would be available on a secondary market, I bet. It still might be better, since not everyone will want to use copyrights on minor works. Then again, you'd be encouraging people to do 'big' works rather than lots of small works, which doesn't seem like something a copyright system should be changing.