That might be true. What's the problem?
What is your specific issue with the jurisprudence in the Dred Scott case?
I have a problem with a method, the sole method for some, of judicial interpretation of the Constitution that could lead to any number of punishments that were kosher in 1790 being legal in 2018.
Differences in judicial interpretation matter; especially when some Justices only consider originalism. Current Conservative SCOTUS Justices tend to be strict textualists; ie, interpreting the law as an average person would have understood it to mean when it was passed.
Consider the following language from Taney's infamous Dred Scott majority opinion:
"A free negro of the African race, whose ancestors were brought to this country and sold as slaves, is not a "citizen" within the meaning of the Constitution of the United States.
5.
When the Constitution was adopted, they were not regarded in any of the States as members of the community which constituted the State, and were not numbered among its "people or citizens." Consequently, the special rights and immunities guarantied to citizens do not apply to them. And not being "citizens" within the meaning of the Constitution, they are not entitled to sue in that character in a court of the United States, and the Circuit Court has not jurisdiction in such a suit.
6. The only two clauses in the Constitution which point to this race treat them as persons whom it was morally lawfully to deal in as articles of property and to hold as slaves.
7.
Since the adoption of the Constitution of the United States, no State can by any subsequent law make a foreigner or any other description of persons citizens of [p394] the United States, nor entitle them to the rights and privileges secured to citizens by that instrument.
8. A State, by its laws passed since the adoption of the Constitution, may put a foreigner or any other description of persons upon a footing with its own citizens as to all the rights and privileges enjoyed by them within its dominion and by its laws. But that will not make him a citizen of the United States, nor entitle him to sue in its courts, nor to any of the privileges and immunities of a citizen in another State.
9.
The change in public opinion and feeling in relation to the African race which has taken place since the adoption of the Constitution cannot change its construction and meaning, and it must be construed and administered now according to its true meaning and intention when it was formed and adopted.
10. The plaintiff having admitted, by his demurrer to the plea in abatement, that his ancestors were imported from Africa and sold as slaves, he is not a citizen of the State of Missouri according to the Constitution of the United States, and was not entitled to sue in that character in the Circuit Court."
You can read the full opinion here:
https://www.law.cornell.edu/supremecourt/text/60/393
Taney was correct in his ruling if one is strictly adhering to a textualist interpretation of law. This method of interpretation was responsible for the single most destructive court ruling in US history, and directly precipitated its most deadly war.
Justices who consider the Constitution a 'breathing' document (at least not completely static) still consider the plain language of the text, but also consider a society's evolving standards of moral decency. Kennedy was a good example of that (see Roper, Obergefel, Lawrence)