But that right is entirely artificial in the first place. It was given in order to encourage more creation. Saying that some creations would have been encouraged had that right been enforced (not even that is a given - a pirated copy does not equate a lost sale 1:1) is not enough to justify copyright without weighing that against all the negative effects of copyright - overhead to licensing, enforcement costs paid by society, people prevented from creating derivativees, etc.
But that right is entirely artificial in the first place. It was given in order to encourage more creation. Saying that some creations would have been encouraged had that right been enforced (not even that is a given - a pirated copy does not equate a lost sale 1:1) is not enough to justify copyright without weighing that against all the negative effects of copyright - overhead to licensing, enforcement costs paid by society, people prevented from creating derivativees, etc.