Respectfully, that's comparing aerodynamic apples and oranges. Rotor aircraft get ALL their lift from the engines turning the rotors, airPLANES get their lift from their wings thanks to our friend Mr. Bernoulli. Their engines are only responsible for propelling the plane fast enough for the wings to generate lift. Yes, multiengine airplanes can absolutely survive partial engine failures as long as the remaining engine(s) can keep them above stall speed. Hell, some airplanes can lose all their engines or engine and can still be glided in for a landing. But, in, say, a quadrotor manned aircraft, if you lose one engine 25% of your lift is gone, not only that, but your remaining lift vectors are severely unbalanced at that point which would be asking a lot of the remaining rotors. You might be able to feather it down for a hard landing, just as chopper pilots can sometimes do in the event of engine failure, but it's definitely a worse scenario than losing an engine on a multiengine airplane.
Thanks to all who've participated in this thread started by my random inebriated question. Have a good one. Also, we're getting some serious snow here in NC this evening, I was wondering if anyone has flown a drone in a snowstorm? Assuming, of course, that it's not windy. I know rain would be a problem, but would a steady but gentle snow cause issues? Just curious (again!).