I gues this "feature" is a sign of higher capacity ships on the way. Right now, the only ship wit an extremely high capacity not yet for pirates are the Ship of the Line class ships. When we get to build our own ships, we should make them the highest capacity ships, like from my thought:
War Ship of the Line:
Capacity cap: 269
Cargo: 4000
268 cannons
49 broadsides (Each side)
Hull: 4,000,000,000
Sail:5,000,000,000
That would make crazy privateer battles, flagship boardings, even crazy raids!