Carrying a pocket knife isn't some great protection of rights. It's a tool, nothing more. Just like a screwdriver, axe, bilhook, sickle, rake, lawn aerator. My point about a knife being a tool you carry for a job, no job for it then why carry it? It's not going to lose you rights by not carrying your knife.
BTW in the wrong place and time I believe carrying a screwdriver will get you in trouble.
I think carrying knives to protect your right to carry them is right out of the American NRA's playback with right to carry guns. I think over here we kind of look down on American gun lobby for things like that. Is it really much different to UK and knives? We have a knife problem like they have a gun problem. If we had USA levels of gun control would they be using guns over here instead of knives and then you knife carriers would not have any fear of carrying knives without a use for them?