Most likely if there are consistently fewer women than men in a region's dance classes, I would chalk that up to demographics i.e a location that has more men, such as Silicon Valley, or near a military base. If there really are plenty of women around, then I might look at other factors. Even then, it's hard for me to imagine that a given class has so many negative issues that it actually would turn off women from attending.
One definite trend is that there tends to be more women for Salsa lessons, while WCS attracts more men. In my group WCS lesson today there were about 150 students -- and all of us men had to stand occasionally on rotations. The last several Salsa lesson had about an even split of slightly more men (sometimes Salsa has more women).