Well ok,
First, I don't understand how you can say Ayn Rand didn't deserve her money.
Secondly, it seems to me that you are saying that the only people producing music that deserve money are artistic musicians. What about entertainers? I seriously doubt N'SYNC considered their music art, but does that mean its OK to steal it? What is the difference of Metallica selling their image instead of their music? If people are still buying their albums, regardless of what you think of them artistically, it proves that are still valued. Furthermore, the fact that people steal their albums proves they have value. Let's say I write a song only to entertain, and work incredibly hard doing it. This song sounds a lot like the Beach Boys-it does not follow any of their chord progressions or melodies, but it is in the same style. Now, let's say I make 10 million dollars of this song. Is it now OK people to steal it? Besides, who says Metallica are not hard working? They might have tried really hard to make an image that would sell well. In fact, they might have tried harder to make that image than they tried to make their older songs you enjoyed. Since (in this theory) they put more hard, honest work into the image than the music that you enjoy does that make it (the image) more valuable? Music is a product no matter how you look at it and just because you personally don't think Metallica's new music isn't art does not make it OK to take it. I think all (including their old stuff) is terrible but does that mean it is ok to steal? No, because no matter what it sounds like, they created so they should have ALL rights to it, saying they shouldn't based on your view of their artistic merit can be interpreted as people only deserve things if YOU say they earned them. Also, I don't think its fair of you to speak for Metallica, they might really, really enjoy their new material. Since they are the ones that created it, they decide the value, they will set a price and if you agree with their set price, you buy it. If you don't, move along. Someone might think the music you make is horrible, does that give them the right to steal it?
To summarize, what I gather you are saying is that if YOU feel something lacks meaning, than its creator lacks the right of private property of the given material.
Regardless of who created or for what purpose, THEY created it and should be the ONLY ones to say how it is distributed, if you get it any other way, you are stealing, it is wrong, this is not a gray issue.