I reverse around corners all the time, especially when I'm at my parents' house... because they live at the end of a cul-de-sac and I have to reverse out of their driveway, round the corner of next-door's garden and into their driveway in order to turn the car around and be able to drive out of the road.
I also reverse around corners of residential roads if I need to turn around and it's not convenient or there's no room to do a three-point-turn.
Of course, I would never reverse around a corner into a main, busy road because that is dangerous, but I don't see why it would be dangerous in a quiet, residential area with no other cars around.