What is the particular importance of Crooks' initial commitment to the idea of buying a ranch, and then his later rejection of the idea?

Crooks is initially enthralled by the idea. Having a part in the farm made him feel wanted... part of a group. He changes his mind, however, after George negatively reacts to Candy's having shared the idea of buying the farm. George's reaction prompts Crooks to assure them that he doesn't really want to be a part of their plan after all.