Social commentary is everywhere, especially in literature, whether we notice it or not. In novels from Animal Farm to Pride and Prejudice, the time period plays a part. Although I dislike the assumption that every snippet has a significant meaning, because it doesn't, writers are aware of the world. And we reflect that in our writing, both consciously and subconsciously.
I didn't set out to write a novel providing political or religious fodder, to showcase my feelings on controversial issues today. I'm a fifteen-year-old girl. I don't do that. I do, however, notice what's going on. I notice news, politics, international relations, social issues, the schisms of society.
Writers may not become great politicians or activists, but they show the current events of their day. Jane Austen illustrated the importance of marriage for women in the 1800s, even though not all women wanted that. George Orwell showed that uprisings from Communists generally don't succeed and are harmful in the process.
As for me? I don't write intentionally with topics in mind; I don't write a certain scene to show how homelessness affects us (that doesn't work very well in my kind of dystopias anyway). If it fits the work, I write it. Someone may see strains of the recession in my writing, another may see something entirely different.
For me, these issues will be a second-draft sort of thing; as I wait until editing time, I'll listen as the world speaks, through news plastered on newspapers and the sides of buses, by word of mouth and email. By the time my novel is done, hopefully the world will be ready to listen.