Actually there are laws about knives that are not really talked about, because they are not an issue. When I was a kid, every boy had a pocket knife collection, and we all played games like "Mumblypeg" with them, and nobody ever thought about stabbing anyone. Swiss army knives were in all sizes. Every kid dreamed about have a switchblade but they were illegal. You could buy them in Mexico. I as OK to have a pocket knife under about a 4" blade, but now schools have zero tolerance for what use to be a harmless thing. They consider any knife a weapon, and take even the smallest very serious.
It was not uncommon for workers to carry a hunting knife in a sheath on his belt. Those can not be carried in most cities. Blade lengths over certain lengths are not allowed many places in folding knives. Not sure about the laws concerning machetes, even if you are a licensed gardener.
I understand your point, and its well taken. I would not recommend walking into the police department with a meat clever.
