I think you misunderstand my argument.
These laws were specifically enacted because of a fear of gang violence, here “gang” being used in the traditional “any non white youths” manner. The law has never been about protecting people, it was about giving police officers another reason to duck over black and Hispanic people.
When a law is specifically created to mess with minority people then it is the responsibility of non racist people to call for it’s elimination.
“During the early ‘50s, the white middle class became obsessed with the alleged danger posed by gangs of ethnic minorities allegedly roving America’s cities. That’s one reason for suburbia and the hysteria is what led to the Switchblade Knife Act, as well as the bans by individual states.”
Note that this is from Gizmodo in 2015, before the… Gawker unpleasantness.
This deals with switchblades, but it fairly much covers all banned knives and martial arts dodads…