Then again, there's some music I respect that I don't ever seem to listen to. Absu past the first album. Gorguts past the second. Metallica after the second. And so on. I don't understand it.
I think I can provide some insight.
If you're like me, when you find something good you listen to it like its a bad habit - all the damned time. You listen and listen and listen, taking in more and more enjoyment until one day, it may not seem so enjoyable. In this case I find "burning out" to be the appropriate phrase. I still love Nuclear Assault but I hadn't listened to them in at least three years before seeing them at this past MDF.
This is generally what happens to me when I find something good. I'm so excited that I've actually found something worth my time, I over indulge. Enthusiasm gets the better of me.
Usually after I wait a few months/years and then listen to it again (sometimes forgetting about it altogether), I'll remember what I loved about it so much, and it becomes an option in my listening habits again.