As I read Mary McKinney's column at Inside Higher Ed, I couldn't help feeling more than a bit ambivalent. On the one hand, McKinney is correct: most departments could do more with people willing to repress their primal urge to whine and less with people who can't tell the difference between a colleague and a verbal punching bag. On the other hand, accusations of uncollegial behavior can be convenient shorthand for "I'm not comfortable with your sex/politics/religion/whatever" (see the CoHE). To make matters more confusing, some campuses write collegiality into the requirements for tenure; others omit it altogether (and, therefore, should not be able to cite it as a reason to deny tenure).
I don't know if academics are all loners at heart, but a number of us confuse two very different things:
1. Our expectation that we will be assessed on the basis of our professional expertise, not on our social failings. We're academics. We like books. Quite a few of us, I suspect, like books more than we like people. This state of mind can generate a certain cluelessness when it comes to social interaction. Of course, some academics would be annoying if they were working at McDonald's. Nevertheless, once we've been hired--a process that includes evaluating the likelihood that current department members may want to permanently lock a potential new colleague in the broom closet--we rightly expect that we'll be evaluated for our scholarship, teaching, and service, not on our ability to play well with others (unless, of course, we've been informed otherwise in our contracts).
2. Everybody else's expectation that colleagues who behave obnoxiously will be treated like obnoxious colleagues. If you behave badly in department meetings, assault people in the halls, and blog about colleagues you dislike without removing all the identifying markers, then--newsflash!--people will not be nice to you. Moreover, they are perfectly within their rights not to be nice to you, because you've demonstrated that you're not a very nice person. (Some colleagues may be more charitable than others.) And they are also within their rights to deny you goodies that require being, if not nice, then at least tactful. For some reason, there are academics who seem incapable of realizing that working with the same group of people over a period of decades may require some modicum of self-restraint.
In other words, I think that we should avoid anything so amorphous as "collegiality" when it comes to tenure decisions--but I also have little patience for those who expect deferential (or even friendly) treatment when they've done nothing but make themselves unpleasant.