Speed costs.
Gets to the disaster sooner, and gets a couple injured folks back to hospitals faster.
How much is being able to get someone 100nmi off the coast to a hospital in one hour worth?
Yes these would be great as air-ambulances.
However in the UK all air ambulances are charity funded, buying / leasing and running these things is massively expensive, sadly i don't see it happening.
Get there quicker, yep, but 8/10 times the patients are transported to hospital by land ambulance, as you have more space, less noise and an extra pair of hands.
The main advantage of an air ambulance is the delivery of specialist care, depending on who's on-board. Could be an advanced Paramedic, and or a doctor. (if your really lucky you get a decent paramedic and an ED doc or even better an anaesthetist)
Heli-med normally have their own dispatcher watching calls, looking for ones they think may come their way. They may contact the ambulance crew to offer help, self deploy or be contacted by the ground team for help.
This or the 609 would be great in the wide open spaces of the US, it would get specialist help to remote patients etc much faster
Now coast guard / Search and rescue would be another option. fast transit to search / rescue and fast transport to hospital, that's where i'd aim my marketing.
UK SAR is now ran by Bristow, long transit times from a reduced number of bases with smaller choppers.
It'll come down to cost, politics and the lowest bider, sadly not what's best for the job.