I think dabbling in satanic things is more a fad among young teens in an attempt to be different or "bad". When I was a teenager (back in the dark ages of the late 50s) doing something like this was unheard of. Two of my grand daughters got into this a little when they were teens but they soon outgrew it and went back to their Christian roots.
This is just my opinion....I am sure the answers you get from those that are into satanic worship will give you a very different answer from mine.
I guess they hate God. I read that they look down on those that do good. It said they like to indulge , take vengeanence , and that man should be free of moral codes. Some were Jayne Mansfield , Sammy Davis Jr. , & the Night Stalker. But there are those that like it I suppose.
Why not? It's basically the same thing as worshipping your god, my God or Goddess, or the Flying Spaghetti Monster. A satanist has found his or her place at satan's side, and I don't really care about anyone enough to worry about what'll come after.
Not that i am a satanist. I'm not. But maybe at least one of them would like to learn more about the devil from a non biased source such as the holy bible. If God truly created him then he probably isnt all evil and may just be misunderstood. However i dont really hold either to be evident i just think that could be the case rather than just assuming that they are evil.