This isn't an issue in the WNBA and Women's basketball in general where the ball is smaller than the men's ball.
As it stands, women are just not as interested in watching sports as men are, with some exceptions like figure skating and gymnastics.
Also, the audience=the customer, so isn't this true for almost all fields? If we are OK with wildly different pay scales in sports because of audience preference, couldn't Hollywood claim the same?
Isn't that the way it is though, movie stars are paid tons more than the rest ?