I'm not sure I see your point? Should we just let them do it then?
In most cases these are people who have nothing but a boat and sailing skills, but their waters have been devastated by a number of things including waste dumping by other countries, oil, and so forth. So they can't make a living from fishing.
So they've no other means of income and no education and see piracy as the only way of making a living, as well as being a form of retribution for the damage that other countries have done to their waters (they don't give a crap what country any ship is from).
The fact that piracy has produced very few casualities is evidence of this. If they were your normal scumbag criminals, they'd just board the boat, gun everyone down and throw them over.
That's not to say that the hostages are treated to breakfast in bed and a happy ending, but they're not typically tortured or otherwise treated very badly by the pirates.
The know the risks but they do it because they don't really have any other choice. So there's little deterrent in a show of strength without addressing the root cause of the problem.
Piracy is inherently risky, there's a reason why it had practically disappeared until the Somali pirates emerged; because nobody in their right mind would do it unless they had no other choice.