I do wonder if it is the difference between slow pitch and fast pitch softball. When I was younger (and I leave near Chattanooga), slow pitch softball was everywhere for both men, women and coed teams. Industrial leagues, church leagues, at the schools - though it was more in the lower grades - point is everyone played slow pitch softball. But it is nowhere to be found and very limited fastpitch outside of the high schools.
Also to note, most girls play in the youth baseball leagues where I live.