According to Atticus, what are three reasons why many Maycomb citizens don't want to serve on a jury in To Kill a Mockingbird?

In Harper Lee's novel To Kill A Mockingbird, Jem observes that people of Maycomb do not serve on juries. It is generally people from the woods sitting on the jury panel. He asks Atticus why that is, and Atticus explains. He begins with the fact that women in this time period were not allowed to serve on juries. Scout takes issue with this, and Atticus explains that it is probably because they do not want women hearing the sordid details of a trial. 

After this, Atticus gives two reasons why Maycomb citizens do not serve: 

Atticus was saying, "With people like us—that’s our share of the bill. We generally get the juries we deserve. Our stout Maycomb citizens aren’t interested, in the first place. In the second place, they’re afraid. Then, they’re—"

Jem interjects at that point to ask why they are afraid. He explains that by using an analogy of the business man, Link Deas. If Link sat on a jury that awarded a settlement to one of his customers at the expense of the other, it would cause problems for him. And that is just one example—the citizens of Maycomb's interests are all tied in together, and not one of them wants to upset the delicate social structure that allows them their illusion of a peaceful and pleasant existence. 

When Atticus states they are not interested in serving on juries, this is partly because of the times—since the novel is set during the Great Depression, citizens of Maycomb have their own interests and problems. It is also because any crimes that are committed likely do not affect their lives, and they do not have a great sense of civic duty. 

The third reason Atticus gives for the people of Maycomb not wanting to serve on juries is found in this quote: 

You’ve many more miles to go, son. A jury’s vote’s supposed to be secret. Serving on a jury forces a man to make up his mind and declare himself about something. Men don’t like to do that. Sometimes it’s unpleasant.

It can be inferred that Atticus means the citizens may have to confront their racist ideas, considering his discussion earlier in the chapter about white men who take advantage of "negroes" being trash.