Sakazuki didn’t join the Navy until his twenties, and he had a very rough childhood, he definitely was not the son of some famous Marine lol
He could be
Just a speculation
56 years ago - Xebec killed his father in the Holy land
CDs mocked the family and Family was casted out....
55 years ago - Family moves to North Blue - Where Akainu was born
He was bullied and had rough childhood.
Developed hatred for pirates - for two reasons
1) Pirate Xebec Killing his father
2) Rise of pirates due to Xebec action which could lead to his family being victim of atrocities committed by pirates in North Blue
Later, he joins navy with Kiz
Rest is history ~ Extreme Justice