There are so many things out there the team needs to get done! New urgent topics emerge every day. And the team is simply too slow to finish all of them on time! The folks on the team are really not productive enough.
To make sure that at least some work is done, team leader puts pressure on the team members. Team leader knows, that without being pushed they will keep slacking. Moreover, it takes them ages to understand what has to be done and why. But the team leader just can't waste time on endless explanations, as she also does as much work as possible herself.