I find it incredible that this type of decision could have been made!! The possibility of continuing on three engines is meant to facilitate airlines to continue onto a 'suitable' airport, i.e maintenance wise, logistics, etc. To argue that from the west coast of the USA to the east coast, onto Canada and over the north Atlantic to the UK, their are no 'suitable airports' is obsered! A 2nd eng failure over the north Atlantic, could have been a possibility. And then, I am afraid he would have to had called a 'Mayday'. Expalin that to the paying pax!! What are we thinking here, economics or saftey?