If untrained people try to defend themselves with a pocket knife they are more likely to hurt themselves.

That simply isn't true, and even if it was there's no system by which trained people can be certified to carry any form of self defense tool.

Even a trained person. A pocket knife is better than nothing, but not by much. Meanwhile a knife is a useful tool in a lot of situations.

That's just not true, knives are quite effective self defense tools that allow otherwise physically weaker individuals to inflict significant harm on attackers without much of any additional risk. I know that in the movies this isn't true, but that's just not a reflection of reality.

To be fair, cigarettes are worse and pipes worse still, especially 2nd hand so it kind of makes sense that everyone was happy to have vapes proliferate.

You mean, people's right to attack other people.

No I'm very specifically talking about the right to self defense actually.

Are you trying to control outlaws with laws? Good luck.

It worked everywhere else. There are less murderers because murder is illegal.