Just your subjective knowledge of your local area and class of home you normally experience.
Not everybody enjoys the security that western democracies provide (although US and couple other countries seem to be slipping behind). In most of the world people with wealth above standard have to actually take special, pretty expensive precautions to preserve their wealth (and in some places lives).
Here people install security to call security company whenever the alarm is tripped. Lack of power is immediately suspect (thieves like to cut power). The security company is notified by the automation and they call the owner for security code. If the owner does not give the security code within required time they will immediately dispatch their patrol. The owner also has special security code in case he is compelled to give one and this triggers a specially escalated response.
So, like yours? When you said "A lot of apartments here have security devices" did you qualify it as "in non western countries with the right balance of affording security services and intenterrupted mains power"?
>Not everybody enjoys the security that western democracies provide
Well, not everybody who doesn't enjoy "the security that western democracies provide" has money to pay for a security company - or even the luxury of continuous power that is not frequently cut anyway, either.
In the context though, in a house with automatic sensors and such, I'd consider my case more likely.
Some might, but I doubt they are a lot. None have such where I am for sure. People would need to turn power off for specific rooms/circuits or the whole thing once a year or so anyway (to do some electrical work, to change some light fixtures, etc). It also happens by itself if some machine overloads/there's a sudden surge. I've changed several rented houses, and it would ocassionally happen to all of them.
As for the fridge, he did say to leave the kitchen (or fridge including) circuit on.