If women choose not to go into computing fields, why should they be forced (or even encouraged) to do so?... How about letting people pick the field(s) they want to go into without telling them what they "ought" to do based on a pointless metric or percentage?
My brain jumped to a few different places when I read these questions. The first is, in pushing for greater inclusion of women, I think there's an implication or assumption that women would like to get into these fields, but are not able to. It doesn't really seem true to me, but maybe some people have other experiences? My experience has been that most of the places I've worked (admittedly doing support, not programming) would have loved to hire more women, and made efforts to do so, but very few women even sent in resumes. But like I said, it's possible that some women could tell stories where they felt discriminated against.
The second thing that went through my head was, it does seem fair to ask the question, "Why are there so few women in tech?" Even if the answer is that women aren't generally interested, it only raises the question, "Why not?" Some people might not like the idea that there's a innate/genetic reason for it, but it also might have to do with our educational system, or something about how technology managers work. It may be a larger societal message, where we're telling women that they're not going to be good at that kind of job. If we had a clear understanding of why women weren't pursuing those kinds of careers, we would then be in a position to say, "That's fine, and not something we want to try to solve." Not knowing what's going on or why, I don't think we can say that it's not something fix. It may even be that women are seeing a problem in the industry that's harming all the workers, and it's a thing that men are just more willing to tolerate. If so, fixing that problem may benefit everyone.
The last thought I had might begin to answer your questions more directly: When you want to hire people who are good at a job, it's good to attract everyone you can and maintain a large and diverse talent pool. It increases your chances of finding the people you need. I'm not even talking about anything related to social justice, but just the practical matter of trying to hire people. You want a big talent pool. As people are fond to point out, it also potentially drives down the cost of labor, but it also increases the changes of finding someone with the exact qualities and skills you're looking for.