100% agreed. This is a habit I've picked up even more heavily from flying small propeller planes. People around your vehicle are unpredictable. Somebody will put themselves in a risky situation sooner or later, e.g. somebody walks into your propeller arc for no apparent reason; a passenger lingers next to your car when you expected them to be inside; etc... Bottom line: shut down your vehicle when picking up or dropping off your passengers. It's so easy to stop and get started again in a Tesla too - there's no reason not to.