None of what Alessandro described is harmful, it is explcitly allowed by the license. You are claiming that there are problems when there are none, it is like having people claiming that the GPL has problems by disallowing a GPLed project being converted into a non-free program.
I must say the analogy is completely wrong, and, I'm sorry, almost specious here.
Care to explain why?
If you wish to have a way to enforce the copyright, then you will need to have copyright papers. Otherwise, you cannot enforce it at all, it really doesn't matter what license you are using. A judge would love to hear "Sorry your Honour, but I couldn't gather the copyright holders to actually sue the accused'.
I do not think a judge would love that, probably an evil lawyer from the other side, but not the judge. I think the judge would actually like to judge facts not handle formalities.
The judge would infact throw the case out. Only the copyright holder can sue for infrigment.
In theory, anyone can go and make Linux a non-free program, since it is simply impossible to enforce the license there.
In practice I think this shows up to be false, otherwise it would have already happened, don't you think SCO would have already done that otherwise for example ?
It has happened, and it is continuing to happen. Usually it is easily solved though.
Cheers.