Very informative post Elliot.
I think what we are seeing here is fear of the unknown, resulting in personal prejudices. Mr. Moose has done the single engine thing for some time, and appears to have done it right. If it's new to you, it probably does seem a little scary.
On the subject of personal prejudices, I can relate that in some 25 years working in flight test and other flying areas for several manufacturers, I have seen many engineering types (self included) with severe prejudices against flying with particular operators, but only one guy with a fear about a particular aircraft type. That was a Boeing field service rep who kept a list of which 707s had which SBs done. He always consulted it before boarding a commercial flight.