Kerzner was clearly a wealthy man. Beats me why people don't buy the greatest safety they can afford when they charter a helicopter. At the end of the day a professionally crewed IFR twin is going to be safer than an R44. I suppose it may well be ignorance - because a piston VFR charter is legal they assume it's safe, but we all know safety is relative. And generally more money buys more of it - which is right. Similarly those that cannot afford an IFR twin should not be deprived the opportunity to fly, providing it is reasonably safe, which of course it is.
It may be no such aircraft were available in the Dom Rep, but there is an issue here. The UK Matthew Harding accident 5 or so years ago being a case in point. How do you educate the customer without provoking unreasonable fear?