Yea, but that's like restricting NYC to Manhattan. I wouldn't feel that unsafe walking the majority of Manhattan at night either.
Or for another city center, I go downtown inner harbor/fells point/federal hill Baltimore at night plenty. Most city centers in America are perfectly safe any time of day.
If the goal is to prove that going to some godforsaken suburb miles out into the countryside is dangerous, sure. This is true in any country. But not if you live in an actual city.
As a Cornishman, this is basically what's taught in the schools, yes. You live in a godforsaken suburb miles out of London but you pretend that, unlike us, you somehow live in a city. ;-)
Pretty much every major city worldwide has large suburbs that have their postcodes and are administered by the same municipal government, but they're clearly not included in the "European city center" designation. They are part of the city, but not part of the city center; and for a multimillion city the difference (and distances!) are significant.