The founding Fathers likely couldn’t imagine a Congress that wouldn’t impeach a Supreme Court Justice for such flagrant self-enrichment. But they were thinking about Congress as a more ideological body rather than a political entity. They couldn’t imagine Justices being aligned with political bodies; that was part of the idea of a lifetime appointment. Put someone in a job for life and they should be immune from partisan political bullshit from the outside.
They couldn’t envision justices who would trade everything for a lifetime appointment to support their preferred political flavor.
IMO, the solution is to let every President nominate a new SC justice, and retire the oldest one every election.