The symbolism is that they're truly not safe; you can still stick yourself on the end and draw blood, which would be authentic. And if you didn't want to bleed you shouldn't have come looking to be a punk, punk. WE SNEER IN YOUR GENERAL DIRECTION.
It's also symbolic because nothing's safe, man.
"Punk jewelry should look like ordinary things, but jewelry manufacturers are already making them for retail sales in precious metals." Because every popular movement gets co-opted and ruined by latter-day poseurs.
Even fake ones like American Punk.