I see it all the time on a cold subfreezing morning. The parents will drive the teens to the bus stop, even if the bus stop is pretty much the end of their driveway, and they will sit there, engine idling, waiting for the bus. Only when the bus comes to a stop will the flip-flopped teen (usually a girl) jump out of the car and dash onto the bus.
So they never really get to experience the discomfort of being shoeless on a cold day.
Why is this so appealing? They like the feeling of being able to kick off their flip-flops at anytime and instantly go barefoot. Too much hassle dealing with smelly shoes and socks.