If this shirt were a person
Usually, when I scroll by a shirt design I don't especially like, I give a mental shrug and click onto the next design. The thing with this shirt is, it's not that I "don't especially like it," it's that if I saw a person wearing this shirt, my first reaction would be to steer away, and my second (if I walked too nearby) would be to glare intensely.
What this shirt means to me is the creepy next door neighbor dude who plays his screaming cacophony and has never thought to respect other people's senses of taste or need for sleep. The phrasing and the font speak of creepy neighbor dude's low self-esteem and a cheesy attempt at raising it. This is just the guy who will with outdated phrases hit on girls far too young for him, and who will only be confused when they spurn him.
Of course, this shirt brings several other comparable things to mind: a vagrant burnt-out rocker, shredded --maybe tarred-- vocal chords, a hand desperately grasping for talent by clawing, instead of manipulating an instrument....
But seriously, isn't this phrase non-specific to metal? In place of "metal," wouldn't "rock" or "country" work just as well (or poorly, as the case may be) in this phrase?
Ah well. I suppose if you actually like metal..., well, now you can buy a shirt to tell people you like metal.