This is me not judging on truth, but just whatever crap TV and movies have forced upon society.
According to popular belief, pirates are generally way more aweosme. Muskets, Cannons, Swords, Seafaring Adventures, Wenches, Booty, and whatever.
Whereas ninja's sit around yapping at eachother doing gay magic and being generally wierd. Also, just running around killing people for no reason.
Pirates>Ninjas