Because black people have only seen things get better for them as time went on. They don't long for a past like white people do. I doubt you'd be able to find any black person who is yearning to go back to the legislated segregation of the '50's or the tumultuous days of the '60's. They have in it progress, because they've seen it first-hand.
The people who tried to keep them down were the social conservatives. And as long as it's the social conservatives who stand against them with regards to police brutality, voter suppression, and white nationalism, blacks won't be social conservatives.
Well as a White Person I don't want to go back to the past either.
Police Brutality-Cops are being shot because Black Men are killing cops so it cuts both way yes Black Men are being shot to death by cops and thats wrong too.
Voter Suppression-77% of Non-Whites agree with Photo ID in order to vote per a recent Gallup poll and 51% of Republicans agree with early voting so lets do both!
White Nationalism-I don't agree with it.