We all bring such different things to the departmental table. A wildly popular but not-too-rigorous teacher is essential thing for any department, because her courses entice more majors and satisfy the bean counters. A rigorous and stern teacher who students fear and only take because they have to is another valuable department member, performing an essential weeding function and providing cover for the rest of us. The professor does an adequate-but-perfunctory job in the classroom but cranks out eh grants and publications is a godsend at accreditation time and in raising the profile of your department. The colleague who is not a great teacher and has not published in years but does yeoman’s work in advising students how to graduate on time is solid gold.
These are very different things, and a strong department needs them all. And if you are really, really good at one or two things and proud of that, it is way too easy to disparage and diminish the essential roles played by your colleagues–particularly if it is someone you dislike. You mentally count the number of times you see students waiting outside the door of your colleague who often misses his office hours, forgetting that he also took a van full of undergrads to the national conference the week before.
It is also true that there are colleagues who bring nothing to the departmental table. But in 15 years at two different institutions, I have never worked with such a person. I have had colleagues I disliked, who let me down or blocked me on important projects or otherwise offended. But objectively speaking, they all contributed to the department. There are very very few genuinely negligent colleagues.