Why does Scout say that Bob Ewell "made himself unique in the annals of the nineteen thirties"? Upon whom does he blame his latest problem on?

Bob Ewell has become "unique in the annals of the nineteen thirties" because he has been fired from a job with the WPA (Works Progress Administration) and is possibly the only man to have the dubious distinction of being fired from this job because of his incredible indolence. Nevertheless, true to his character, Ewell places the blame upon someone else: Atticus Finch.

During the Great Depression, President Franklin D. Roosevelt instituted various social programs to...

Bob Ewell has become "unique in the annals of the nineteen thirties" because he has been fired from a job with the WPA (Works Progress Administration) and is possibly the only man to have the dubious distinction of being fired from this job because of his incredible indolence. Nevertheless, true to his character, Ewell places the blame upon someone else: Atticus Finch.

During the Great Depression, President Franklin D. Roosevelt instituted various social programs to provide relief for Americans, who were out of jobs and virtually starving. One of these was the WPA, which provided relief to people, but at the same time, it allowed them to retain some pride because they were assigned jobs rather than just given a free check. So, most men were very grateful to be earning something for their families. While a proud man like Mr. Walter Cunningham refuses such a job because it is a government-provided one and, therefore, an insult to him, in contrast, Bob Ewell is so worthless that after accepting this job, he is too lazy to even work. 

Of course, as is characteristic of this man who typifies "white trash" in Harper Lee's novel, he blames others for his failure:

...his job lasted only as long as his notoriety: Mr. Ewell found himself as forgotten as Tom Robinson.

When he returns to the welfare office, a worker there named Ruth Jones says that "Mr. Ewell openly accused Atticus of getting his job." The only reply that Atticus makes is in telling Ms. Jones that Bob Ewell knows well where his office is if he has a complaint to make. Moreover, this latest vignette on Bob Ewell clearly indicates the sordidness of his character, preparing the reader for his final ignominious act.