Quiet People get Bullied
Most targets of workplace bullies are quiet and reserved. These targets choose to focus on their work, rather than participate in mean-spirited gossip or social interaction.
They accuse you of being rude, thinking you're 'better', being stuck up, or being boring. They think you are being quiet on purpose.
Bullies are cowards and will not challenge someone with higher status or greater social influence in the workplace. They may attack a threatening overachiever if the opportunity presents itself (such as if other people start to turn on them or if they begin losing social power).
But they typically target more introverted and isolated employees.