With such politically charged issues, it's always a problem of people wanting to believe something is possible (and mandatory to pursue) banging their heads against what is true and actually possible. If the percentage of female computer science graduates (as a strong proxy for the available candidate population) is 18% (Google for the facts and stats), how is every company to hit an idealistic goal of 50% representa…
I think the idea behind diversity targets is an implicit assumption that they do. In subtle ways like how/where they advertise, and in more obvious ways like funding educational programs etc. It's there that diversity programs/targets need to start, not at the hiring stage.