One thing that stands out when thinking about basic security requirements is the need for security in depth or “rings of security” any protective system without depth/rings of security will eventually be broken. To put it simply if you only lock your perimeter fence gate, but leave you front door open, sooner or later someone is going to jump the fence and walk into your house.
This is an interesting concept, especially in light of modern 'outdoor living' design trends.
Go back to the country-style or Californian bungalows and there is often low or no front fence and a large verandah (for much of the front of the house or sometimes even all around). This often had chairs and maybe a table and cupboard for storing stuff.
From about the middle of last century this shrunk to become a porch, hardly big enough for umbrellas and shoes or to provide shelter when arriving home and fumbling for keys on a wet night. But front windows (typically the lounge and master bedroom) remained large and may have got larger.
When internal access from the double (or triple) garage to the kitchen became popular the front porch disappeared. High walls are more an inner suburban thing - they're a significant expense for the outer suburban project home buyer. But on project homes front windows became narrow slits, more like medieval castles as the most commonly used lounge moved from the front to the rear of the house.
Outdoor living is the big thing, with the ideal being a flow from the kitchen through a living area out to a deck and then, if you haven't yet hit the back fence, a few metres of backyard. The wider the rear doors open (first glass sliding doors, then bifolds, and then the whole rear of the house) the posher the house or reno.
So as people made the front of their houses more fort-like and closed off from the street, the back became more open, to match peoples desire for flow between inside and private areas outside. Only a wall of glass - no brickwork - seperates the plasma from the outside.
In this regard I agree that you're only relying on fences with neighbours and in this regard new homes have quite poor security due to our taste for inside-out living and a withdrawal to the rear. Meanwhile as people are almost always at the back of the house, and street views are less sought after, there is less passive surveillance of the streets.
