To continue Fareastdrivers argument,with our litigous society, if one flew a profile that was outside of the recomended Flight Manual or SOP from the emergency section of the Ops Manual, you can be sure that one (at least) passenger would suffer from some sort of post-traumatic stress. Compensation about never being able to fly in a helicopter/work offshore again, from a smart lawyers angle, could amount to a huge amount. And of course, where one went, others would surely follow.
The opportunity to practice autorotative approaches, without passengers on-board, would be minimal, so the chances of a successful one in an emergency would accordingly decrease.