Removing copyright tries to eliminate the moral choice and therefore the freedom. Freedom, in any real discussion of free will, has to permit the person to act wrongly. That's not free will. In the final analysis, cooperation or non-cooperation is a moral decision made personally at the individual level. One legal coercion or the other will not be determinative to overcome anyone's free will.
Law can never make people better than they are.
The personal struggle each developer goes through is a good thing in the ultimate understanding of his own morality. Have faith in the goodness of people. If a majority of people aren't good, nothing can help us, anyway, not GPL, not law, not heaven. But history has shown, I think, the moral goodness of the majority of people. The current proprietary system, while giving them legal freedom to cooperate or not with copyright, coerces them economically, since it pays them to not cooperate.