Why is this important?

Enthusiasm on someone’s part will help him or her to hold the interest of his or her listeners; it may also rouse them to action. If one is enthusiastic about what he or she says, the audience will be too.
Enthusiasm helps give life to a talk or speech. While it is important to have informative material, it is a lively, enthusiastic delivery that will help capture the attention of an audience. Regardless of one’s cultural background or personality, enthusiasm can be cultivated.