There's another aspect to this, I think, and not to beat up on personalogic ...
For me, the measure of a successful program isn't really championships or state titles -- rather, it's the experience the girls have. As I've said before, if a girl looks back on her high school basketball sometime down the road and thinks "I'm glad I did that," then that's success.
An indirect measure of how girls feel about the program, I think, is how popular the program is within the school -- and a simple measure of that is how many girls want to be involved. There are a lot of choices in high school, from other sports to other extracurricular activities, so if girls are choosing basketball instead of say, lacrosse, or choir, then that's a sign that they are hearing from girls within the program that it's fun and worthwhile.
That kind of word-of-mouth also trickles down to middle school, and when freshmen arrive on campus, they know what they've heard about various activities.
So if I look at a varsity roster and see seven seniors, that tells me that those girls have a good experience their first three years -- and even more so if they're borderline players. And if the JV roster is full, and at larger schools, if there's actually a freshman team, that's an even greater endorsement of the head coach and his program.
If it were only about basketball, then sure, having a 12-girl roster makes sense, but since 99% (or whatever number) of the girls who play in high school will never play in another organized game, I think a program's goals should be more about the experience than about winning the most games. And the more girls who get something from the experience, the better ...