And yeah, the WNBA ball is smaller but, seeing as how it's the same size as the FIBA ball, it seems like a legitimate tradeoff, as it were.
Regardless, it is smaller than the NBA ball because someone decided that the NBA ball was too big for the WNBA women, due to the average hand size of WNBA women versus NBA men. I am sure they felt that they could handle the smaller ball better and shoot it better.
What's the difference between that and saying that the women shouldn't try a litle bit lower rim, since the average WNBA player height is much, much less than the average NBA player height? Easier finishing at the rim, and all the other reasons already mentioned.