It's true. When I was first introduced to heavy metal (the album Sagas from Equilibrium to be precise. Much recommended) I could immediately appreciate the musicianship and catchy and folky nature of the melodies (the panflute player on it is apparently among the world's best and also worked on the LotR soundtrack) but the heavily distorted guitars and especially the guttural screaming of the singer were really strange and off-putting to me at the time and I kept thinking, "why don't they just omit the vocal track? It'd sound so much better!" but there wasn't an instrumental track so I kept listening, and slowly but surely I started to tolerate the guitar tone and vocals (but the latter not much more than that).

After a few years of not having listened to it I picked up the album again and, would you have it, the vocals actually sounded perfect to me now! I realized how they actually fit right in with the wall of distorted guitars, as if they were an extra rythm guitar. An instrumental track would actually be so much more boring! Funny how one's perception can change so much over time/mere exposure