The acceptable accident and death rate will always vary between countries and cultures. It's a philosophical issue, and I'm not sure there is a right or wrong answer to that. Zero accidents by HEMS crews is one ideal, and a few accidents but fewer patient deaths because of lack of transport is another. It's a continuum without a firm boundary, like all moral issues. Should we let one person die to save many others, or save those we can and take a chance on many more deaths? Each person will have his own opinion, but I don't think any of them are necessarily right for everyone or everywhere. The US philosophy is the US philosophy, and the British philosophy is the British philosophy. Both are valid, but only for that locality.
To put it another, ruder, way, opinions are like a$$holes. Everyone has one, but the stink is in the nose of the beholder.
Another opinion I have is that you can't cure stupid. The profit motive has relatively little to do with press-on-itis, IMO, and the pressures are mostly self-imposed. My company has very strict weather minimums, and goes out of its way to remove pressure to fly. No one in the company has the authority to question the PIC's decision to fly or not, at any level. It's the pilot who decides to keep going in deteriorating weather, not the company's, and I believe that is the case in almost all the HEMS companies in the US. The hero mentality is dangerous, and I try to dampen it any time I see it. Anyone who is in this business to save lives is in grave danger of killing himself and his crew, but there are those who see the job that way. I don't know of a way to stop it, because you just can't cure stupid. Ignorance yes, but stupid, no.