Well actually it was a boy who said no (we can have a a discussion another time about the number of men in administration in women's softball). President of the International Softball Federation, Don Porter, has rejected baseball's proposal for a joint bid in the Olympic games.
It was a pretty quick decision. The respective presidents met on Thursday (remember at baseball's urging), Porter said he would think about it and then issues a press release Friday morning saying, "no thanks." (Makes one think the ISF was never really into this plan.)
ISF believes its best chance for reinstatement is to prove to the IOC that they are not baseball. When they were voted out in 2005, members of the IOC thought the two sports were basically the same and had the same governing body.
Softball also wants to stay away from baseball's doping scandals, which have not waned (i.e. Alex Rodriguez) and which will likely keep baseball out of contention.
In short, baseball was hoping softball's good girl image would rub off on them and softball is worried that baseball will keep dragging them down.