I wonder what kind of use did the legislators have in mind when it was decided what could be a 'legally ok to carry' knife?
Because, to be fully honest, we do not need to carry a knife!
Nobody uses a pensil, use strings, and so on.
Of course the trades that need a knife are allowed to carry whatever design and blade length suits them!
I think I must be the Last Boy Scout because I am always prepared. I don't/can't leave my house without being prepared for 1,000,000 things unlikely to happen to me. I carry and use pencils, string, fruit, even a small bit of fatwood (as a keychain) etc...
In reality though most times I've used a pocket knife away from home have been food related but also cleaning nails, removing splinters, pencil sharpening, turning fallen branches into impromptu walking sticks (and swords), whittling, making pooh sticks, collecting flora and once fixing a kite.
Granted most of these aren't necessary but it's nice to know I have a pocket knife in case I need it.