Pirates had little to do with it. What destroyed the Quaker colony of Pennsylvania was a huge influx of non-Quaker settlers, wanting equal access to government, combined with worries on the part of the British government that a pacifist Pennsylvania would weaken British power in the colonies. Pennsylvania stayed pacifist for a number of years, and had every Pennsylvanian immigrant been a Quaker, it would probably be pacifist today. By the same argument you're defending, it would be perfectly honorable for me to kill someone who wasn't attacking me if it would advance my family's well being. I'm sorry, but my family's well being is not a good enough argument for brutality.
Pacifism can absolutely work as a universal absolute.
We don't believe in that 'humanity is born to sin' stuff. You might want to read George Fox's journal. He is quite clear on the subject. All rights reserved.