It's not a conscious choice people make. It's a subjective perception issue, which is harder to fix. Example: In a room with a male and a female founder, most people will ask the male for technical help, while assuming the female is less competent technically. Interviews are highly subjective, so is wage determination.
That might be because a lot of women prefer other fields. If you pick a random female and a random male, chances are the female has far less relevant tech experience than the male. Even in "tech," they're more likely to be HR, graphic design, or a paid tweeter like Adria Richards was before her lack of basic git hub knowledge led her to try to bully people out of their jobs.
I can actually see myself doing this, if I didn't know both people. But is that because I'm male or because I think males are more competent? I don't know.
