I think this is probably true in legislative bodies and in government agencies - for the same reason: both promote deal making because there's something to be gained.
One of the reasons the SC Justices are seated for life is precisely to blunt that effect. They can be friends without needing to make deals because they really don't get anything out of a deal - and one hopes they fully appreciate the gravity of their position.
The Court is a sort of unique entity in that it doesn't need (I don't think) to be confrontational in order to be effective. It is the one place where one would think, true wisdom reigns. And by and large, that is what I see from SCOTUS' decisions.
It's a sign of an intelligent, mature mind to be able to contain contradictory ideas without losing your identity. Being friends with someone on the other side of the political aisle, in a group as small as the supreme court, I would think has the effect of improving the quality of their deliberations and little else.
A competent rhetorician is only "hard to hate" when you don't look at what they do. Keeping one's eye on the ball is not that difficult when you have a set of principles.
If you disagree with that, I suppose we'll have to agree to disagree. It was sort of incredible that Scalia basically straight-up says "You gave me the power to decide whether abortion is permitted nationwide? Really? Who thought this was a good idea?" (Not an actual quote; the talk is quite good.)
Apparently it wasn't always so, and Scalia explains the history too. The concept of the constitution as a "living document" was manufactured, along with the idea that morals mature over time. "Societies only mature, they never rot! /s"
What you're talking about is a matter of business. There are certainly some individuals that it would be quite difficult to be friends with in spite of what they've done. But if Scalia is one of them, well... Everyone has their preferences, I guess.
Antonin Scalia's entire worldview was built because he knew he was a rear-guard for regressive thought and maybe, just maybe, a broken country with an impotent federal government could allow people like him to continue to kick the shit out of the weak a little longer. He was never going to get to punish women with an abortion ban (and today, would never get to fuck over trans people) nationally--so the natural outgrowth of this is to punish women and fuck of trans people where they can. All in the name of "letting people choose", so they can choose to vote on the basic humanity of others.
I reject the idea that one can "be friends" with the people who want to bring the long dark back. They will break civil society on the anvil of a supremacism that exists to benefit me, and I refuse it.
But, after watching Scalia, how can you not like him?
https://www.youtube.com/watch?v=Ggz_gd--UO0&ab_channel=Ameri...
https://youtu.be/TRS-jdgHok4?t=105
He was witty, charming, and a master orator. So when people hear "can't have a friendship with Scalia, even though you work with him," it's kind of like "can't breathe, even though you're human." It's a logical contradiction. And it's not even a well-defined problem: what is a "friendship," anyway?