Your first link indicates that, as I said, the purpose of redlining was to direct wise economic decisions. Some researched (linked from wikipedia) suggests that the data may have been biased against black neighborhoods due to bias of the appraisers. It does not suggest that the purpose was to specifically screw over black people.
No That wasn't the reason why redlining existed. It existed because it was explicitly racist policy enabled directly from the National Housing Act of 1934[0] -- which was basically just codifying the existing racist attitudes of the day.[1] It stemmed from the racist idea that blacks were inherently bad neighbors in all ways you can imagine. To say this was merely a good enough heuristic, or even the result of government over reach is grossly misunderstand the historical context of these policies. These policies were not any more controversial than saying, we should not zone a preschool next to a oil refinery.
[0] https://en.wikipedia.org/wiki/Redlining#History
[1] http://www.theatlantic.com/magazine/archive/2014/06/the-case...