Leaders are often harsh and very critical. The best ones are critical and still know how to operate a group. The Harsh boss who is always on you to do something is often just hurting himself because by pushing a single worker, he isn't able to keep an eye on the rest and by expending all of his energy into one, he won't have any energy to get through the day. From the worker stand point, they wont want to come to work. With a demanding boss who is always in your face, I wouldn't want to go either so I wouldn't blame them.
The best leader hold high expectations of the group while still having fun with it. They are able to make the employees or group member want to come to work instead of having to come. These are the most efficient leaders because they will have the best group morale and will be able to accomplish more than any one else.