They may not be poor, but the point is that if you live like that, and get arrested, even if you are innocent and released within a few days, you may have lost your job in the meantime, or have incurred fees that you can't cover, or something else the knocks down the house of cards that is your finances. It doesn't matter if you make minimum wage, or $300k/year. If you spend all of your paycheck before the next one arrives, any unexpected cost is going to break you.