If activity A is beneficial to x% of people and detrimental to (100-x)% of people, then we should expect, in a perfect world, to see x% of males and x% of females attempting activity A.
Suppose A is beneficial to 80% of males and 40% of females, and detrimental to 20% of males and 60% of females; why would you expect, in a perfect world, to see 60% of males and 60% of females attempting activity A?
Suppose A is beneficial to 80% of males and 40% of females, and detrimental to 20% of males and 60% of females; why would you expect, in a perfect world, to see 60% of males and 60% of females attempting activity A?