In almost every movie or TV episode when a door is opened, the character doesn't bother to shut the door after passing through. Why? Would it kill the flow of the story?
Woo - one I know! - often sets are temporary structures and if you slam a door it can make the whole wall wobble (this is often seen in poor-quality shows or ones from the 60's/70's). So many floor managers have just become used to ensuring that they aren't slammed by cast members - even if it's a real set just out of habit. In fact I've seen in scripts lines such as "Door slams [ensure solid door]".
for YEARS i have noticed, and now watching Stranger Things - again, get out of the car, leave the lights on. other times, walk through a door, do not close it... i theorized it is to keep the feeling of continuity going. turning off lights or closing doors [especially when entering, not when exiting like leaving home] would render a change in flow and be distracting. bugged me for years, good to finally Google and research it a bit, and find others noticing the same thing. ah, the beauty of the internet 8).