A difference is that the anti-copyright position is quite generally agreed (and also seems rationally well-supported). Disavowal is not merely a wild personal impulse.

And a/the virtue of any law is that element of general agreement, not just that it happens to be the law. So to do something agreed on but not law seems righter than to do something that is law but not so much agreed on.

Perhaps it could be put simply as: ultimately the law should follow us, not the other way around.