We all like to defend our airplanes till the end and have little regard for folks that say anything other than glowing remarks or agree with us. I'm sure the PC-12 is a great airplane and so are MU-2's....in the right hands. I would love to own either one just has soon as I win the lottery.
Bottom line is...most folks identify safety with numbers. Two or more engines, generators, vacuum pumps (they still use those?), hyd systems, pilots etc..are better than one. Over the BIG pond, in the weather or at night....I personally want all the redundancy and backups I can cram into or on an airplane! One engine now makes me nervous, I don't care what the safety record or stats say. I've flown PT6's, Garrett's, RR's, GE's and Pratt's along with piston Lycomings and Continentals. I'm here to tell ya.......the more the better.
If you're twice as likely to have an engine failure with a twin, 3 times more likely with a 3 engine aircraft and 4 times as likely on a 4 engine aircraft, I can tell you that if you lose an engine on a single......you ARE on final approach and you WILL be landing soon!