The only thing worse than having a problem coworker is having management who is on their side.

From the perspective of a boss, few things are more important about managing people than trying to keep the peace. Happy, or at least not disgruntled, employees are a lot less likely to quit on you and leave you with the headache of filling another position.

Still, there are a lot of bad managers out there. They often make decisions that are supposedly about fairness, but end up causing more problems than they solve. Being an employee under these conditions can feel impossible, and at its worst, it can be actively discriminatory. Few things are more likely to get a person looking for a way out than dealing with management that does not appear to want to work in their interests. If they appear to favor other coworkers over you, that is just the cherry on top.