Assuming an air worthy, serviceable PA31 of any flavour has an engine failure are you suggesting yesterday's accident is the inevitable outcome?
Having practiced full feather shut downs in the Chieftain/Navajo I think some of these comments are pretty far from the mark. Have returned to land with one close to idle due to a prop malfunction at close to max weight. There were a number of operators who had in flight shut downs during the crankshaft plague who were able to fly to the nearest aerodrome (or further) and land. The performance is not great but it should climb, let alone maintain level. If your PA31 failed to climb or maintain altitude clean on one engine at low level there is something wrong.
Report it get it fixed before someone has a real problem and relies on that performance.
CAO 20.7.4
8 EN-ROUTE CLIMB PERFORMANCE
8.1 Multi-engined aeroplanes engaged in charter operations under the Instrument Flight Rules or aerial work operations under the Instrument Flight Rules must have the ability to climb with a critical engine inoperative at a gradient of 1% at all heights up to 5 000 feet in the standard atmosphere in the following configuration:
(a) propeller of inoperative engine stopped;
(b) undercarriage (if retractable) and flaps retracted;
(c) remaining engine(s) operating at maximum continuous power;
(d) airspeed not less than 1.2 VS.
8.2 Multi-engined aeroplanes (other than those specified in paragraph 8.1) must have the ability to maintain height at all heights up to 5 000 feet in the standard atmosphere in the configuration specified in subparagraphs 8.1 (a), (b), (c) and (d).
If it can climb at 1% it can maintain altitude at that height. If the aircraft can not achieve this at max structural weight the take-off weight must be reduced.
Light twin aircraft have a higher accident rate, piston or turbine, due to the nature of the operations.