In real life, I'd say "vous" to older people because they were raised that way and you should show respect to them, and I would do the same to people in power (boss and such). I would not say "vous" to a colleague or someone younger, that would be weird for me. I don't like my students telling "vous" to me either because it makes me feel old! (actually, if I would call someone "Monsieur" or "Madame" then I'm likely to follow with the "vous" but if I call them buy their first name, then it's unlikely)
In films, they make say "vous" all the time as it sounds a bit romantic, maybe? Or maybe the film director is old and old fashionned? It's everyone's guess.