Teamwork is an integral skill in most office jobs.
If employees want their workplace to function like a well-oiled machine and, perhaps more importantly, if they want to keep the amount of unpaid overtime they are doing to a minimum, they have to be willing to work together to get whatever results they are aiming for. Not every colleague is going to be your friend, but finding out the best way to collaborate with them can pay off in terms of your long-term peace of mind.
Unfortunately, pretty much anybody with any kind of work experience has realized that not everyone is going to clock in with that team-focused mindset. Sometimes, their reasons are justified, but other times, they just wind up creating roadblocks and extra work for everyone who is invested in actually doing their job. It is frustrating to deal with, and it can leave a person with no choice but to take action.