Mmmm, I guess I don't see how value to society-at-large is a central factor in determining a person's value to a private company, where the primary goal is to maximize profits.
My simple assumption is that gross earnings are maximized by employing the most talented group of individuals possible, while profits are maximized via some function relating each person's talent (roughly translated as their propensity to foster earnings for the company) vs. each person's cost (salary).
If Woman-A, Woman-B, Man-A, and Man-B are all attorneys of similar cost (require same salary to recruit), the most pragmatic move is to hire the most talented among them. If this isn't happening, there is some underlying inefficiency lurking; and it could very well be gender bias.
Now, as for a metaphor, I think the bank robber thing is far too abstract; instead how about this... Say there is a law firm specializing in criminal law. Specifically they defend people charged with murder. Consider that innocent people charged with a murder are, on average, easier to defend than people who actually did commit murder. This means that... the better this lawfirm is at their job, the more actual murderers they will successfully defend.
I think it's safe to assume that absolving actual murderers has a net negative value to society. As a law firm, I don't give a single shit about that. OJs of the world are simply not interested in paying thousands of dollars to law firms concerned with whether their acquittal will have a net positive value to society-at-large.