No, this music is Satanic. Or I suppose technically Luciferian, for those who consider the two to differ, and for whom that difference is important.
Rock music, metal, or really just about any genre of music can be about any subject matter.
But ultimately it is a means of free expression and you can think of it as fiction, just like movies if you like. And as with any fiction there will always be people who take things way too seriously. See the fan following of the Bible for example.
Seriously though I don't mind people having a belief. It's all a matter of how far they take things. Absolutely not a fan of hardcore evangelical types.
I was tempted to say musicians don't intend for their fans to perform violent actions perhaps present in their music, and for most musicians I believe this to be true, but then I'm reminded of, for example, Burzum. So yeah I'm just going to have to say I believe it uncommon.
Think of it like this. You watch a horror movie. You don't then go out and chainsaw massacre your neighborhood do you? Well I would certainly hope not. Because most people can tell if something is a fiction.