Even America's most admirable people were products of their respective cultures. We can learn from their repugnant moments, just as the older Atticus can serve as an example not to follow. But we should treasure the moments when these figures transcended their times and stood for democracy in the broadest sense.
Being that Atticus Finch doesn't require that we attend white supremacy meetings, support police brutality or poison our own children with hate. It merely requires that we maintain our innocence amidst the maw of institutionalized racism, and mask our complicity in that system via periodic outrages at current events that clash with the saintly pictures we have painted of ourselves.