Many workplaces have one - the person who's so burned out, unhappy or angry that everyone wonders why he or she doesn't just leave. It should be a career goal of all of us to never be one of those downers. There are some practical reasons that people stay in jobs they hate.
Health insurance is a big one.
Good pay, proximity to home and family loyalties are others. If you wake up every workday thinking that gargling hot pepper sauce would be preferable to going to your job, it could be a clue that you're in downer territory. If these clues hit close to home, it's probably time to move on. You are not happy at work, and you're probably infecting your co-workers with that unhappiness. There are dysfunctional workplaces where no sane individual would want to stay, given a choice.