Did it ever occur to you that just because your old man was a hardened man of the streets, not everyone is? There are lots of people who do not have the physique, mental fortitude, or training for self defence. Nor, frankly, should there be. While I am of course not against self defence, having the whole city's population brawling each other would surely spark more side conflicts and would end up creating a much more violent city than there already is, especially if everyone views themselves as the undefeatable main character of their story.
And you failed to address the question of what happens when someone loses their job because of this vigilante justice you've proposed? It's easy to tough type words behind a keyboard. When you have to keep a roof over your head and food in your mouth, more rational decision making prevails.