It would be grand if the US supreme court justices were all robots who could parse an issue and look to the constitution in a cold, objective, scientific manner, but they're not. In the real world they all bring their own biases, influences and political motivations to bear in their job, which is partly why it can't be left up to just one of them. This so-called "calling balls and strikes" approach is rhetorical nonsense, but even if one does subscribe to originalism or textualism at least as a guiding principle, why is that objectively better than the "living document" approach? And if we are so concerned about the founders and what was thought at the time a law or amendment was passed, one thing we know for sure about the founders is that they were very concerned about tyranny of the majority (although these days its more the over-represented minority which is the problem) and the dangers of populism. And let's not forget that the Warren court was abhorred by the right for its supposed "judicial activism", starting with Brown. That arguments have since been made for the Brown decision from an originalist perspective doesn't change how they were perceived for years. They and subsequent courts correctly got out ahead of the government and the electorate on a whole range of issues, not just segregation, and people's lives have benefited from that.
Personally, I'm perfectly fine with the constitution being interpreted through a modern lens. Hopefully Alito's decision doesn't lead to the rollback of many of the gains society has reaped from that approach. Otherwise, good luck winning back any of those rights with the Republican party holding so much power.