Air ace, this guy was clearly level headed and capable of handling the aircraft on one engine. The problem is the aircraft does not have the performance on one engune.
Assuming an air worthy, serviceable PA31 of any flavour has an engine failure are you suggesting yesterday's accident is the inevitable outcome? This is not the first engine failure in a PA31 series aircraft and I am also aware of another PA31P engine failure in Australia many years ago, which had a different outcome.
Piper PA-31P-350 Mojave at Max Gross 7,200 pounds:
Rate Of Climb: 1220 fpm
Ceiling: 26500 ft
Rate of Climb (One Engine): 255 fpm
Ceiling (One Engine): 14300 ft
Sorry, but I do not accept your:
"....this aeroplane cannot perform on one engine and is dangerous."
I'll wait for the competent, authoritive ATSB report for the causal events which may have contributed to yesterdays accident. I am sure there were more issues, considerations, events or decisions involved, than a single engine failure.