Nice story, but don't learn too much from it. Your reaction is
understandable for a new PP with pax on board, but not for someone
with some more time and experience. Such a flight is safe and
only slightly more at risk than fog-free throughout the flight.
Engine failure on any flight can be "catastrophic". Now it would be
stupid and fool-hardy if you didn't have a plan B if your destination
forecast was wrong and also fogged-in: alternate destination with
surer VFR, ability (fuel) to turn around and go home, etc.
--
The major difference between a thing that might go wrong and a thing
that cannot possibly go wrong is that when a thing that cannot
possibly go wrong goes wrong it usually turns out to be impossible to
get at or repair.
Douglas Adams, Mostly Harmless