I think its less about people living in the city and more general light pollution. Light pollution spreads a lot further than you think even for places you think are a full starry night sky. I know in my own life, the difference from my urban house, to a more rural cabin is huge, but the jump from that rural cabin to the middle of Boundary Waters Canoe Area is also huge. I assume if I ever get a chance to go to an International Dark Sky PLace there will be another large jump.