I kind of see it as the reverse. The 60s were glorified as hippies and peaceful marches changing history when it was actually bloody and crazy and knowing that the white youths being scared of the draft combined with minorities starting to get more and more violent means that the country had to move a different way to flourish.

Less about showing the past and more about hiding the darkest parts of the past.

Look at how few people knew about racists bombing black prosperity until Watchmen came out.