They are romanticized as Robin Hood characters not only in movies but in books. Frenchman's Creek by Daphne du Maurier, for instance.
In truth, they were not only thieves and murderers but rapists and by means of living on shipboard for months or years, smelly, toothless and scarred. Many of them missing appendages - hands, arms, legs - due to sword fighting.
I liked du Maurier's book ... but I don't like pirates.
They are the sea-going version of home invaders and very scary people who still exist.