It has more to do with the basic fact that the west has no stomach for civilian casualties. The only time we would be willing to attack is if we managed to get them on their boat on their way to a hijacking, other than that they make very sure they have civilians with them, be it Somalis or hostages.
There is a solution to the problem, but the number of governments willing to make the move is small.
This is the crux of the problem. We have no credibility in our threats. I say sink every one these “rescue” boats, save as many hostages as we can, and leave the pirates to the sharks. As to this town of Eyl that the pirates call home, wipe it off the face of the map!
From that point on position naval vessels just outside of Somali territorial waters and threaten to board every thing that leaves it.