Also, I fear that groups of women programming might not get the same experience as if they were also programming with men. I'm skeptical of the value of gender-biased environments helping defeat perceived gender biases found in a particular activity. It seems it would only further promote gender biases.

The program fails if most of the women, upon exiting the program, start programming with men and say "This isn't like Ladies Learning Code!" and either quit programming altogether or simply join other groups of women to program.