Would any number of weapons really help four people with limited or no combat experience on a smaller boat? If they are facing a relatively large number of pirates, it would seem like the best they could do is take out a couple pirates before they were killed.
Which might be better than what happened to them anyway! In related news Seattle citizens wonder,”Would tires be good on a car?”
It depends on the situation. There have been cases of yachts successfully fighting off pirate attacks. The main strategy in that area is running in convoy, for mutual support. It’s much harder to attack multiple yachts that can fire on you from several directions.
Keep in mind that this yacht was attacked more than 1000 miles from Somalia. Their range of operation is as big as the USA east of the Mississippi.
And just as, for example, one person with a CCW could be overwhelmed by a gang with assault rifles, that does not mean CCW is useless. In most cases, a CCW pistol will stop an attack. Same on the ocean with a yacht. I always carried a rifle and other weapons.