Respectfully disagree. Dred Scott was a horrible decision, but the alternative was to stake out new ground. This is merely stating the law is the law.
In it’s impact, while a very different kind of case, it would lead in time to a conflagration that would essentially end the country that existed at the time of the ruling - when the country came out of the war between the states, while nominally intact, it is was a very different country than the one that went into that war. This ruling will have a similar impact.