I'm not really for these laws, and I've read the local paper quoting the County Sheriff (Macomb Co., MI) as saying he doesn't support them either, on account of how he'd have to arrest all his neighbors. Most police forces, as far as I have ever seen, will not enforce them unless you are being wreckless with explosives, like shooting roman candles at cars, or something. If you live in a state where good fireworks are illegal, odds are you still live within reasonable driving distance of a state where they are not. You know what I mean.
They do have a purpose though, and in states where fireworks are cause for legitimate forest fire concern, I definitely understand why they exist. On the other hand, if you're dumb enough to blow part or all of yourself up, the least your home state could do would be to allow it to be very pretty.
In Southeast Michigan, last week, some lady killed herself at work. The employees at the car wash took up a collection, bought some fireworks, and she leaned over a three inch shell for some reason. Gore galore. Those sorts of fireworks should be very illegal to purchase by people without permits, I agree. But most of the regular stuff that people like doesn't pose that sort of lethal threat.