The interview process is all about being biased against certain candidates. But what often happens is that the biases we hold when interviewing and working with candidates don't matter to the job but happen to exclude people who would otherwise do quite well.
It's not like interviewers are all twirling their waxed mustaches and snickering about how many women they've excluded. But what they do is listen to how someone describes a problem or how they behave during a whiteboard interview and interpret that negatively simply because it's different from what they were expecting. And so they don't hire the person because they're a "bad culture fit." Some women have been trained by our culture to use less assertive terms to avoid showing dominance in a discussion. And they tend to wait for you to finish before they talk.
Or suppose that the people at the company tend to wear a certain gamut of colors because they're all white and blue-ish and grey-ish colors tend to look better on white guys. So when someone shows up with a redder shirt that person might be taken as "too flamboyant" when in reality they're just picking a good neutral color for their skin tone. It just happens to be a significantly different tone from the rest of the office.
It could even be as subtle as discomfort with inexact or flowery speech. I had a lead who would get very uncomfortable when I would talk in metaphor and use metaphors and different words to describe things in terms that he wasn't used to. He would try to get me to tone it down. But everyone else on the team was perfectly okay with it so I kept doing it. That's another form of useless bias, because I was understood and could do my job but probably wouldn't have been as hire-able if I had talked like that during my interview.
My point and OP's point is that discrimination is frequently not overt. We have to look past these superficial differences and really think about whether someone can do the job. And we also need to be exposed to more candidates who are not like this. So a program like this stuffs the pipeline and gets us more exposure, and it's now up to us to challenge our existing biases and try a more diverse array of people out.
