You said that 67 votes should be required for appointment to promote bipartisanship (or politically neutral judges). My point is that this hasn’t helped much elsewhere.
Because bipartisanship required by the filibuster could be circumvented by changing the Senate rulebook with 50 votes on a party line....
They are, primarily, not partisan. They are appointed by whichever party because they have a view of the law which tends to yield results that party prefers. In any case, this has heretofore been quite unsuccessful, but my point is that they reach these results not because they are Republicans/Democrats or chosen by Republicans/Democrats; they are chosen because they are likely to reach those results.
As for why there is such a spectacle, I think this is because both parties have realised that it is more enduring and effective to get their ideas deemed as enshrined in the Constitution rather than getting people to vote for them. (This is a flaw of the constitutional system.)
Right, so the claim that justices "aren't partisan" is semantics.
Mitch McConnell isn't an idiot. If Republican and Democratic justices didn't exist, then he wouldn't have bothered blocking Merrick Garland. And RBG, also not an idiot, would have happily stepped down under Trump to preserve her health.