Individual Germans may not have thought of themselves as particularly bigoted against Jews, but that didn't stop them from participating in regimes that marginalized them.
Most of the people fighting against slavery owned slaves. Jim Crow persisted well into the sixties and it's probable that many of the people against slavery would have been for Jim Crow.
It's very possible for the hiring market to be biased against liquidity even when everyone wishes it were easier to hire.
The market is made up of individuals acting in their own self interest. Why would any individual not make hiring easier if they thought they could gain from it?
Note that Jim Crow/Davis Bacon/etc was a legal regime, a "must discriminate" set of laws to prevent people from acting in their own self interest. What such mechanism exists today preventing me from acting in my own interest?
I replied to you elsewhere but I did just remember that Google / Apple poaching deal. That isn't even a bias, but outright manipulation at a massive scale that hurt the market more than any bias probably could. I am just wondering where in the hierarchy things like this go vs. subtler market forces you are theorizing.
Well, things evolve over time. Market manipulation would be slavery, while bias is just Jim Crow. The whole world is operating under a biased, ugly regime, it just gets better little by little over time.
If it gets me good people to defect (make my hiring easier), I win. The world won't copy me so once I hire people, I can still keep them.
I don't do this because I don't think I'll get good people.