All very interesting viewpoints, keep them coming.
Yes, the recent EMS accidents in the USA were not attributed to engine problems (except the downtown Washington medstar one in may 2006).
Maybe 2 pilots is safer than 2 engines? Given most accidents are caused by pilot error?
I personally think the twin-only 'rules' are hangovers from when engines were not particularly reliable.
I am willing to bet the fatality rate in the USA (much more single engine use) is no worse than in the Europe (much more twin engine use)