There's a few things going on here:
1) Many in these communities see success and virtue as intertwined. The idea here is that a person with the correct traditional values plus hard work and faith will have a good economic outcome. If God is present, and God commands us to act in certain ways, surely he will reward us for our faith in all aspects of our life (including the economic dimensions).
2) A person living in an economically depressed area won't have money to hold onto, and his life is usually just a few ticks away from financial ruin, losing his home, losing his car, major health episode, etc. It's an ugly and chaotic state. Traditional values provide constancy and a psychological anchor. I may be in a chaotic state but God is in control, even if things go horrifically bad. The trade-off here is that God sets the rules that everyone has to abide by.