You propose what you think should be a better solution. This history so far shows that your solution is not clearly better. Just this month "The Consumer Financial Protection Bureau issued a bulletin warning employers against using only so-called payroll cards to pay workers." ... "Complaints received included fees for withdrawing cash and checking card balances. Critics say payroll cards with high fees mean that some workers are essentially making less than minimum wage." -- http://www.usatoday.com/story/money/business/2013/09/13/agen...
Yes, there can be a time where that's a better solution than a check.
However, we are not yet at that time, so it's not a rational choice NOW.
Prepaid cards, fee-free for the user. Seems like a basic necessity for an economy to work smoothly.
A bank account is not that, at all. A credit card is closer to that (because of chargebacks). Prepaid credit cards, and getting a new one every month (carrying over the balance, and because of the number changes, it's very hard to charge you things you don't want to pay for), are better still. Cash is best.
You want to improve the situation of 90% of America's poor ? Find a way to convert a check into a prepaid credit card (with balance transfers from a previous prepair card, ideally), for as low a fee as possible. Make that option available in poor neighbourhoods. When you have that, offer a bank account to them as well, NOT linked to the credit card, fee-free (no-one will care if it's also interest free) that they can save money into.