One of the reasons things are much better now are because laws against discrimination change what is socially acceptable. As regards the market handling it, we needn't speculate, just look at the actual history of racial discrimination in the US, from white-only diners to schools, that was only overcome by direct government intervention.

You can be optimistic all you like that we'll "eventually get there" (I'm not) but optimism doesn't do much for people whose rights are being infringed today.