Would money privacy matter in a world where you would be punished severely and without exception for even attempting to take advantage of another person?
Think of places where stealing is stealing. Whether it be a persons life savings or simply an apple, your hand is cut off.
A court rules that your advertising or contracts were likely crafted to create confusion and get people into different agreements than they reasonably believed (non transparent and fine print type stuff), so your fingers are cut off.
A person of honor will not ask you to give unless it is determined to be an absolute need, AFTER careful consideration of the effect on your well-being.
It would never be in any way stemming from selfishness or manipulation, but from ethical principles.