If there are biases upstream of that point in the process (such as "those with a social security number ending in 9 are admitted to law school at one-sixth the expected rate"), then I'd expect an unbiased hiring process to result in that same discrepancy in those hired (presuming here that social security digits are entirely uncorrelated with performance in law school and the practice of law).
Should the law firm work to try to eliminate that upstream bias? Sure. Should the law firm work to hire in a biased way such that they end up with an evenly distributed outcome? I personally don't think so, but I understand others who think they should.
If there is some other bias present, the solution is to rectify that bias, not force diversity hire. Forcing diversity hire is a lazy solution, a way to *not" actually fix the cause of the problem.
Lots of people agree that color blindness would be the ideal world, but seeing that the world is not color blind, trying to advocate for it seems like a way to continue pushing an injustice instead of addressing it.