"they just want the music and apparently don't care how they get it."
That is pretty much the core of a lot of this.
Specifically addressing out of print material - I hate to sound cruel about it, but that's a hazard of what's going on. If your fans don't have the ability to buy the material and REALLY want it, they're going to find a way. Whether it's someone selling bootlegs or informal trading or online downloading, it's going to happen somehow. When a performer lets material lapse out of print, the assumption is (hopefully) that the demand for said material is more or less over, and it's no longer financially viable to produce it. I personally believe that (at least on an independent level) the way to avoid this is to make sure that there's always material available. The group I'm with always keeps a stock of all of our releases laid in - we only run 1000 copy runs at a time, but this way we ALWAYS know that if a customer wants to buy the material, they can get it. It's not a huge expense, and it's covered us on several occasions - we don't ever have to tell a potential customer that something is out of print, even though our first release is around 10 years old.
BTW - most of our members either are or were Napster users. With Napster dead, others use edonkey2k, Morpheus and the like. I don't, mainly because I've not been able to find anything worth the pain of dealing with my slow connection. The general consensus is that we HAVE had several discs sold to customers who'd never have purchased our recordings without the online downloads - we've had people at our shows tell us very explicitly that they're there because they've downloaded and liked us.
Yes, there are abuses. But there are VERY definite positive points that can be made. To simply immediately define every single person that uses the services a thief, and to claim that they have no beneficial effects, is absolutely preposterous.