I would have thought that the biggest danger when picking up pax in an uncontrolled area would have been somebody walking into the tail rotor. It doesn't matter how often or how well you safety brief people, they still want to walk around the back.
When picking up unsupervised people I get out as soon as I land to get control of the people, especially in a 206 if the baggage compartment is to be used as it is behind the cabin.
No doubt it would be safer to shut down on every pick up but its just not practical or even possible in a lot of cases.