The difference between the grazed and ungrazed areas is striking. The land may become worthless for future grazing because the mature dominant plant may be indigestible. A casual observer could conclude that biodiversity is enhanced by grazing animals. But that analysis would be flawed as well. What we should divine from this example is that nature's balance resists our efforts at control and that grazing, in and of itself, is neither good nor bad.
Balanced grazing leads to a balanced grazing environment.
The ancient practice of moving domestic herd animals to mountain pastures in the spring and to lower elevations in the fall followed the cycles of growth and renewal and prevented overgrazing. Mother Nature didn't seem to mind that arrangement.