I've spent 30years working as a pro photographer, and my work includes occasional survey work from helicopters... six hours a day sitting in the door of a LongRanger wearing a survival suit, a harness (with quick release toggle) and waist belt while operating pro camera gear. I love the work, but it should only ever be one photographer in the door... not five.
The problem is that nowadays everyone with a DSLR or even a iPhone wants to be a professional photographer for a day, or an hour... and both society and industry is indulging these individuals. Yes, they get to fly about in a helicopter for an hour with the door removed, but as with most amateurs treading into pro territory, most never appreciate the challenges or dangers until it is too late.
Professional aerial photographers, like professional pilots, know the risks, practise procedures, work to checklists and usually have a higher level of awareness beyond the viewfinder than most amateurs ever would... a 10-minute prep talk before a door-off flight is not enough to prepare amateurs for what pros spend careers learning about and practising.
Some things are best left to the professionals. Had all five passengers been wearing conventional seat belts with both doors on the helicopter firmly closed, even with the hard landing there is a good chance that helicopter would not have immediately flooded with water, and all five passengers might possibly be alive today. Sad.