The flaw in the "it's not big enough" logic is where do you draw the line? If, for example, a ferry with 200 people on board is sinking then a Sea King or S61 isn't big enough either. If the majority of rescues involve lifting 1 or 2 survivors,and I don't know what the stats are but I would guess it's in the 90 - 97% range, then surely an aircraft optimised for that role is the best use of limited resources?