As a musician, it especially kills me to watch people destroy their ears. These workers are often too young to appreciate good health.
"I used to, but the acid kept dissolving them."
I think it's more than what you've described. I think it's that a lot of folks actually prefer dangerously loud volumes, and this contributes to a positive feedback loop of expectations for loud concerts. I wish most concerts were quieter, but I may be in a minority.
Anyway, the solution for "it's quiet at the back" isn't "turn it up at the front". It's line arrays, distributed speakers etc.
I support everyone's right to destroy themselves if they choose to do so.
If we don't have the right to destroy ourselves, how can we also have rights to build and better ourselves? How can we be said to own ourselves at all if we can't choose to destroy ourselves?
The idea that we can't be allowed to choose to harm or destroy ourselves is the most fundamental violation of the most basic of human rights.