I think you're confusing what works in theory vs the current state of affairs. At many companies if you speak of "you're dealing with humans" and "way people think and act" in a hiring process you're automatically inviting interpretations that can be used to justify the reason you didn't hire someone was because of discrimination. Simple as that.

If you really want to see change in the world stop preaching truth to believers, but instead root cause the problem and find solutions that address them. In this case, legislation.