"discrimination" is a very vague word. Technically all employers practice some kind of discrimination. Applying for a job is an exercise in getting discriminated against (typically for your skills, education and experience).
The key here is that discrimination against someone for their race, sex, sexual orientation, religion, etc. is unethical, no matter what kind of social wrong you aim to right.
Giving women more opportunities may seem like it's progressive. I mean, "we're helping women"! But it still contributes to defining people based on their gender, rather than their skills and abilities.
I worked at a company a few years ago that would ONLY hire women to work at the front desk. This was a deliberate move to make the office look more diverse than it actually was, because most of our male employees worked outside of the view of our visitors.
That, and the CEO openly admitted that he enjoyed "seeing a pretty face every time he came to work".
How do you separate my blatantly sexist employer's hiring of women for visibility from social-justice oriented businesses doing the same thing to "further women"?