Because the majority of roads nowadays in use were built in 1830... /sarcasm
Here, even 70 years ago, several roads were just a dusty path through fields and many of them didn't exist yet. When they were actually built as a road, it was done for cars, buses, trucks and it was done from steep consumption taxes on gas and later from country-wide toll imposed on cars.
Of course, YMMV in your country. But I really think that you didn't have asphalt-paved 10 m wide roads 180 years ago.
That is very nice in the situation you described (e.g. someone is shouting threats at you, especially in the comfort of your house), but pretty useless in most other situations. Unless you have a police officer walking with you 24/7/365, when you find yourself in front of attacker, you may or may not be able to even call the police and when they arrive, they would only collect evidence around your dead body.
Yes, the attacker would be then removed from the society (usually only temporarily and only if they are found) and some possible new attackers would be deterred by the idea of being found. But before someone like that is convicted, they must perform or try to perform their first crime. Is this some kind of duty, if someone happen to be that first victim, to remain defenseless and sacrifice themselves? Also there are incidents such as road rage or crime of passion, when the attacker has no previous history.
PS: Even in the situation you described (guy making threats outside your home), the police may be, and often is, late, when the guy (or more of them) decide to get into the house. Calling the police and waiting for their arrival takes at least minutes. Unless you have a fortress, making a way into your house takes seconds. Recall the woman who had to shoot two robbers while still talking to 911 operator.
>The absurd idea that we all each take self defense into our own hands is just ridiculous, just as you don't build your own water supply, or generate your own electricity, or train to be a doctor just in case you get sick.
Then I suppose you also shun the idea of CPR or the first aid in general. That's what first world society has doctors for...