I'm actually not really into hard/rock metal lol - it's not a natural interest of mine. Red actually made the mistake of diving into pop rock for an album, and I picked that album up because it was amazing. This led me to dive into their entire music discography. I like the lyric interpretation puzzles as well.
Plugged In didn't assume it was satanic off the bat - what they were worried about was that some of their lyrics could be misinterpreted as violent threats. I listened to the album in question, and I agree that is a valid concern if you listen to songs out of context and don't understand what the band is really about. I also don't think the violent stuff is going to go away either - there's stuff to suggest that their latest album is about mass shootings and the proper Christian response to that. I think we can both agree that's mature content that would be rough for kids to process.
I have to be honest and say that the media discernment thing never caught on in my family - I was watching the Patriot at 5 (a rated R movie) at home and then later had to get permission from the school to watch a cleanfix version at 10. So I'm trying to do my best to be careful here and read all the relevant information to the amount of media I'm listening to before putting stuff on here parents may not want their kids to watch. I figured Lindsey Sterling was okay (I watched that video like 5 times before posting it evaluating everything from the wild west musical "combat" to the skirt length of the main performer because I'm a nut). But Red is too much.
On the other hand, I am actually excited for the new album (heh) and find said music good for coping with my moods. Part of honesty about myself without leading kids into stuff.