Why did the court choose not to “turn the clock back to 1868” when considering the issue of segregation in public schools?

Plaintiffs opposed that restricted public schools are not "Equal" and that thus they are destitute of the equal protection of the laws. Because of the obvious importance of the question given, the Court took jurisdiction. In approaching this problem, we cannot turn the clock back to eighteen sixty-eight, when the Amendment was adopted. We must consider public education in the light of its full development and its present place in American life throughout.

Why do you have to ask such hard questions.