What does Atticus mean when (in Ch. 22) he says to Alexandra, "We've made it this way for them, they might as well learn to cope with it."?
The whites of Maycomb have created a hostile place for blacks, but the blacks should probably just learn to do their best with the unpleasant situation until one day in the future when it might be improved.
The well-to-do people of Maycomb have profited from a system which impoverishes people like the Ewells, so that it is no surprise they have learned to get by with nothing by breaking the rules and lying.
He and his sister have been at cross-purposes for so long without dealing with their differences that it has created a tense environment for Jem and Scout, so it does not matter if they hear them arguing or not.
People like himself have both done a disservice to and tried to show kindness to the Cunninghams, so that it makes sense the one of them on the jury should vote "not guilty" to try to stay on their good side.
Maycomb's adults have failed to deal with their differences and examine their prejudices, with the result that those ugly biases will go on to affect their children, so there is no harm in the kids having attended the trial.