If memory serves there were 20 Somalian criminals aboard the boat when the SEALs got there. I hardly think that an elderly couple with a shotgun would have discouraged them. The smartest move on their part would have been to not go anywhere near the area to begin with.
They were attacked more than 1000 miles from Somalia.
If you are sailing around the world, Africa presents you with a choice. The Red Sea or the Cape of Good Hope. 50 foot waves against a five knot current can also kill you.
Until recently, yachts have been convoying through the Red Sea, under the eye of the USN. I don’t know about this yacht, but it was more than 1000 miles from Somalia and had probably not even reached the convoy assembly area.