This is a very general question. I have nothing against these people. Even I listen to classic heavy metal. I've always seen classic heavy metal as a harder version of Rock. But, other subgenres of heavy metal have death growls and screams. I've seen many people who are agnostic or atheist who end up listening to Thrash Metal, Death Metal, and other harder subgenres of Heavy Metal. But I can't get myself to listen to these subgenres as I can't make out the lyrics and can't handle the death growls and screams. My question is do people who are atheist and agnostic find anything in these subgenres that other subgenres don't have? Or are they just angry at something and end up listening to screams and death growls? Or is it the other way around? I know that most subgenres of heavy metal don't have lyrics against religion. So, that probably isn't the reason. I'm just curious.
Like topo says in his comment above: God creates them all. Men and music.
It must be an error from both sides. Music is harmless and can’t be bad.
This is probably the cliche and prejudice:
Bad people - bad music!
Like some church people may think like this ... so there will be agnostics who attributes themselves with such cliches. Well, it is known music underlines our feelings and helps to live and express our protest aswell it can lead to meditation, ceremony, military march, dancing, worship etc.
I’m grown up in a religious community. In the sixties we had formed a pop-band, the genre heavy metal wasn’t known to us but we composed and also played this style to reach all kind of folks.
We loved the contrast. Of music ... and of people.
At first, let's agree that we only look at average values and statistics here. Then yes, I would also state the observation that people with agnostic or atheistic beliefs do listen to thrash and death metal more commonly. This is just my own observation - I don't have any data on this!!
We can look at how and when these styles are created, and what topics and themes the lyrics feature. Death / Thrash / Black - Metal themes often feature topics like "rebellion, death, Rejection of the concept of a loving god, criticism of religion and religious groups" ... stuff like that. In that sense people listening to that music might as well treat the concept of a deity with more scepticism.
I can however only speculate why death metal and harsh vocals did coincide with the mentioned topics.
I do not think there is a direct link between religious believes and preferences for musical genres. If you find scientific studies that support your view, I will be happy to discuss this.
Death growls/screams are yet another tool in the giant toolset of creativity. They can underline the song's message, e.g. think about a song that deals with injustice - it would make perfect sense to scream the lyrics here.
Yes, I agree with you: often the lyrics are hard or even impossible to understand. But usually you get the lyrics from somewhere. There is a myriad of examples where the lyrics contain a lot of cultural references, hence it is helpful to have the printed lyrics at hand anyway.
Some years ago, I used to skip such songs too but over time I got used to this kind of singing and nowadays like it.
Additionally, growls fit the instrumentation better in many cases - that is when using heavy distorted guitars, as they give more weight to the human voice.