Final answer:
Professional people in Maycomb are considered poor due to being 'land poor' in an agricultural society with strained credit systems, and the widespread economic hardship of the Great Depression affected all social classes.
Step-by-step explanation:
The professional people in Maycomb are described as poor due to a variety of historical and economic conditions. In the context of the American South, being "land poor" was a common state for many farmers and planters. They grew much of what they required themselves and had little cash available, relying on credit systems that were strained by war and its aftermath. In Maycomb's case, this would translate into professionals like Atticus Finch, who accepted goods for legal services because money was scarce. Furthermore, the Great Depression heavily impacted all classes in Southern communities, leading to widespread financial hardship. Even educated professionals would not be spared from the economic strife of this period, making their situations analogous to those of the physically poor.