Re: copyrightholders can't always (ever) maintain their state-granted monopoly
Clearly society values creative works, hence the urge for some people to obtain them through whatever channel they choose, illicit or otherwise. But as Bunbury pointed out above, if the professional creators are not adequately compensated for creating then they will stop doing it, and then only those who dabble will be left to produce inferior stuff just for the 'fun' of producing it. That's a race to the bottom, and everyone loses in the end.
As I see it, the purpose of copyright law should be to allow a creator to be able to claim enough reward for creating so that (s)he will go on to produce more works for everyone's benefit and enjoyment.
I think the 'lifetime plus <n> years' thing is unreasonably greedy and provides a kind of self-justification for people who rip stuff off - but I also think the people who insist that all copyright should simply be ignored are just as greedy, wanting to obtain for nothing the results of someone else's efforts.
Copyright is indeed a kind of state-granted monopoly, but if we as a society want to enjoy creative works, how else can we ensure that it's worth the creators' while to spend their time and money producing these things for us?