Sometimes, the people who disappoint you the most aren't the ones who do the wrong thing; it's the ones who know better, but don't stand up for what's right.
Before deciding on the next math department Chair at Ohio State, the Dean interviewed all the tenured and tenure-track faculty, one by one. He reported that the main concern of the faculty was a lack of collegiality. He said that three names recurred in the interviews. Around the (purely metaphorical) water cooler we asked each other "Who's the third?" Not because we couldn't think of a third one, but because there were several possibilities.
Of the three "non-collegial" faculty, the first two were obvious. One I'll call Nick Machiavell (not his real name). Soon after I arrived at OSU, Nick told me the useful and important observation that "collegiality" is a codeword that academics use to marginalize people they don't like. While there's a lot of truth in that, it was also an excuse Nick used to ignore criticism of his behavior.
For example, Nick often disagreed with our colleague Greg, but he might phrase it by stating that Greg was stupid. Greg recalls standing up at a faculty meeting and asking everyone, "why do you put up with this behavior?" After one of the times that Greg pushed back, Nick implemented a new strategy. Right after Greg said Y at a faculty meeting, Nick, rather than calling Greg stupid, said that anyone is stupid who says Y.
Nick and I often had the same views on what the right outcome should be. But he and I had very different views on how to achieve that outcome. Nick became so unpopular in the math department that when some of us (including Nick) wanted X to happen, the best strategy was to try to prevent Nick from attending the meeting at which X was discussed.
Hamlet Prince (not his real name) was well educated, well spoken, and well respected by his colleagues. Ham wanted the department to hire R for one of our postdoc positions. R had a strong file. Nick told me that he was against the appointment, since "eastern Europeans are lazy --- they stop working after you hire them." Nick added that he knew this was an "illegal reason" to not hire someone, but that he'd deny saying it, if I told anyone.
I let Ham know that I and others would support his proposal to hire R, despite Nick's objections (which Nick had also told Ham, "illegal reason" and all). However, Ham (who was a tenured full professor) told me he decided to back down since standing up to his colleagues wasn't in his best interests.
Without the strong support of Ham, who was closest to R's field, the department wouldn't offer a postdoc position to R. While I understand the need to pick one's battles, I wished that Ham would choose to fight more of them.
Greg was eventually so miserable at OSU that he accepted a job offer elsewhere. Shortly before he left, I asked Greg if Nick drove him out. He replied that it wasn't the Nick Machiavells of the department who drove him away, it was the Hamlet Princes. It's the ones who know better, but aren't willing to do the right thing.