It seems the battle between pirates and ninjas rages on. But after careful reflection, I'm going to have to side with the pirates on this one. While I'm sure ninjas are extremely well trained and very good at what they do, a pirate's life is much richer and freer, and just plain more fun! Ninjas must spend so much of their lives training to perfect their ultimate fighting skills, they don't have time to really enjoy life.
Pirates understand romance. They know how a faded and torn map leading to buried treasure really inspires the imagination. I think this sense of romance comes from living in such harmony with the sea. They know the joy of an invigorating breeze of salty air. What do Ninjas know of joy? Nothing - joy would just be a distraction to them.
The piratical life is very sociable. You live in close quarters with a bunch of friends. You drink a lot (fresh water spoils fast on the open ocean so beer and rum is what there is). Ninjas don't have any sort of social lives - they trust no-one.
You know what else is great about pirates? Prosthetics! Eye patches, peg legs, hooks for hands - you name any body part and some pirate somewhere has an artifical one. Completely awesome!
And for all their talent and training, Ninjas aren't so undefeatable. They can really only win by sneaking up on people or poisoning them in their sleep. A ninja with a sword is no match for a pirate with a flintlock pistol - the pirate would just shoot the ninja dead before he got within a sword's length. And Ninjas' hovering powers? They work great in trees and on ceilings, but fail utterly over water, the natural habital of pirates.