You are ignoring the RadALT CB. If you don't think it would have made any difference in getting under the cloud base then nothing I say will convince you.
The ACTUAL, TESTED, decision resulted in all passengers surviving.
The rescue attempt was to the SE of the island. It was only a stroke of luck that:
The firefighter who had used the different route to Kingston Jetty reported stopping on the cliffs to the west of the airport to visually search for the aircraft.
that they survived the ditching. No calls to alert anyone where they were going to ditch.
The survivors reported that most of the life jacket lights had stopped working by the time they were recovered by the rescue vessel.
The survivors were very fortunate.