Here in the U.S., requiring such things (and the large, expensive helicopter you'd have to have) would mean that many communities would simply be without air ambulance service as the cost would be prohibitive. If you're cool with that, fine.
Well if the FAA and local authorities are 'cool' with VFR helicopters falling out of the skies with monotonous regularity then I suppose the situation will continue. There comes a point when the argument of having any EMS helicopter rather than the right one just doesn't hold up.
And it is not simply a matter of providing expensive IFR capable machines - the crews need to be well trained and current otherwise when they do fly IFR they may well 'flounder around for a while' before crashing.