please god no.
It's one thing to have legislation meaning that venues playing music at potentially dangerous levels should have to provide earplugs on request, another thing entirely to ban loud music altogether.
it'd be counterproductive anyway IMO, as clubs would react by installing crude limiters in an attempt to keep the music below the legal limit, DJ's and bands would then end up responding to audiences shouting at them to turn it up, by pushing the mixer to it's limits, and you'd just end up with way higher levels of distortion in clubs.
Distorting systems being the ones that cause the most damage, therefore IMHO limiting soundlevels across the board would be more likely to increase damge to hearing than decrease it.