Even the best pilot in the world would have landed in the sea had he continued to 20ft without sighting the runway
What a strange statement. I would guess that about 80% of the guys I fly with ( that's over 100 people) could fly the 737 from the MAP to the threshold using a basic instrument scan of vertical speed , airspeed, and by aligning the noodle with the dashed white line of the runway. Would any of them do it ? No way, they wouldn't even contemplate it. If nothing seen at MDA....."going round flap 15".
But they could if they had to.
Mind you, they all have many hours flying IFR in turbo props and pistons. Maybe that's the difference.
I find it amazing how much variation there is between airlines.