How does the account of whitey's quitting contribute to the book's mood of alienation?

Whitey's leaving contributes to the theme of alienation by reinforcing how really alone the migrant workers were. No one knows why the man really left (Candy claims Whitey said it was the food), and no one care enough to ask. Candy noted that it was normal for workers to up and quit..... these men had no attachments, no familes, and no home base.

"Why... he... just quit, the way a guy will. Says it was the food. Just wanted to move. Didn't give no other reason but the food. Just says 'gimme my time' one night, the way any guy would."