I know what you mean, people that over-engage themselves to the point that they can't manage their own workload end up creating a toxic work environment and taking it out on their coworkers. In my experience when those people leave the organization morale and retention goes up for everyone else.

The point at which someone becomes 'over-engaged' is highly individualized but based on my experience it is highly associated with people that are deliberately working their way up the management ladder.

A sociopath would be someone expecting OTHER people to work up to burnout, for his own sake.