"Universally" makes that statement useless. Vermont only allows sparklers. That is practically a ban on fireworks in the context of this discussion. Many other states have strong restrictions, partially for sake of reducing injuries (and noise and fire risk).

And there is constant advocacy for stronger restrictions/bans.

The point is, we do restrict people's actions on fireworks and guns in order to prevent larger costs. They are not a counter example for why the Coast Guard should have done nothing in this case.