You don't "need to" but reducing the prop wash is a nicety. It's the kind of thing the pilot does in commercial operations (to improve the customer experience)

You don't "need to" but reducing the prop wash is a nicety. It's the kind of thing the pilot does in commercial operations (to improve the customer experience) when there's textbook perfect VFR conditions and 10k of margin below you if you run out of power/lift and have to dive out of a stall. It suffices to say marines jumping out of the back of C17s and C130s are not getting that kind of polite treatment. Even if you've got a bunch of well practiced skydivers, having them all get out of the plane quickly and close together is going to make for a much better experience for them. Everyone is gonna pearl clutch about it being "dangerous" but prop washing the crap out of your skydivers also carries some danger. As the video indicates a stall at 10kft isn't really a big deal for a halfway competent pilot. I wouldn't call it a daily occurrence but elevator pilots (skydive pilots) recover from a stall far more than most because they're constantly climbing as fast as possible (because that's the most economic way to run a skydive operation). Considering the kind of pilots who wind up doing skydive operations I think a lot of them would have been tempted to just take their hands off the controls and see if the plane recovers itself (it should) and then intervene if it doesn't. There is no real "answer" here because the activities involved have some baseline danger to them and at best you can just shift it around between parties. Imagine the fallout if someone bumps the horizontal stabilizer on the way out the door and does even the slightest damage to it or gets a minor fracture or something. It's a big f-ing mess. A stall and a bunch of hand wringing is clearly the better outcome for all parties.