Fin Keels have nothing to do with seaworthiness; they're about speed/production costs = profits. Do a "loses keel" on Google. Check out the images too.
You seem to have a trauma with losing the keel. Do you know how many Benetaus were produced? Well, they make between 1000 and 2000 a year, make a guess!
Do you know how many keels where lost? I never heard about a single one
If you make radical very low weight racers the chances are that if something goes wrong on the construction or the architect calculations are too optimistic, they may have problems with the keel. But anyway on those boats keels should be checked regularly and they are not designed for bluewater cruising.
I have given you an example with Benetau and that is not a boat designed specifically with bluewater cruising on mind. Now regarding those bluewater boats that I was talking about : Malo, Halberg Rassy, Najad, Moody, Oyster, Tartan, Morris, Amel, do you ever heard about any problem with a keel?
So why a fin keel if properly designed and produced is lesser safer or make a boat less seaworthy? Fin keels are more efficient and they do the job better than full keels and that’s why NA are not using full keels anymore