What does Atticus mean when he says, "this is their home: we've made it that way for them, they might as well learn to cope with it."?

This is after the huge injustice of the trial. Even though Aunt Alexandria has softened, she maintains that the kids should not have heard what went on at the trial. Atticus says that the trial was part of reality in Maycomb. Their innocence can't be protected forever. What happened was part of the town's legacy and part of theirs as well.