You assume that banks are using racism to keep blacks and other minorities from getting homes. If that was the case you would be correct.
However, the problem with your logic is that most banks comply with the CRA, where the Justice Department brings down their hammer as in the recent case with Wells Fargo was that blacks and other minorities were being charged higher fees and interest rates, even if their credit and income was close to the same.
Therefore is lending is flowing to minorities but banks are charging them more. While some racism does exist in the system, I think a majoritity of these charges show up because of a lack of knowledge by the borrowers not because of some overt racism.
That's because their default rates are higher, so there is less likelihood of getting the money back.
I suspect it's affinity exploitation - wherein minority salespeople take advantage of the ignorance of the minority clients they serve. This kind of thing shouldn't be difficult to flag given the fact that everything is computerized these days. There'd be less of this type of discrepancy without affirmative action in hiring, since incomes would track ability, rather than today's reality, in which legally-mandated racial preferences promote favored minorities above their innate abilities at every level of employment. Nonetheless it should be possible to companies to filter for this kind of affinity exploitation. The downside is that protected minorities will also have higher default rates at every level of income, since the ability to handle money is correlated with innate intelligence, and most protected minorities make more money at a given level of IQ than their white or Asian counterparts, thanks to Federally-mandated racial preferences.