This dialogue occured after Chinaski wrote a report of complaint about how the job was flawed. But he left saying that Mr Johnson is a fine man. He also complains that the “Union man was worthless”. Very typical Bukowski who recognised the hopelessness of the underclass, being ignored and trodden on by the powerful. His grave reads “don’t try”.
The impossibility of delivering the mail come up in Bukowski's writing throughout the novel. For a contemporary take on this see the recent dispatches documentary Post Office Undercover