The point is they should. In regards to your last sentence they do put you in jail for not showing up to court.
I agree we should but it is a tall order. We are by far the most litigious society in the world. Also, they put you in jail for failing to appear in court not because of your inability to pay your debts. Furthermore you are only detained until the judge is available to hear your case, in other words you are held in custody to assure your presence.