That phenomoneon is quite hillarious really, that people turn a music genre into a lifestyle, in the modern sense of the world that is, you could say that metal was a lifestyle for its creators too, but in this case it was not about conforming to a preexisting norm, instead they rather created the norm with their way of living.
Metal still take up the majority of my listening time, but I certainly am not limited to it. For example, as I am writing this post, I am listening to Kraftwerk's Trans-Europe Express, something which would be impossible for the metal addicts as they need to uphold an image.