Why does Crooks think that Lennie’s story about the farm is a dream “that never comes true”?

Crooks has been at this ranch for a long time. He has seen transient workers like George who has land on the mind. They all want a place to call home because they have no home. At the same time these men cannot save money. They are so lonely that they cannot resist the temptations of alcohol, brothels, and other temptations of the town.