(2) After a year of this, the wife has a baby and works just 20 hrs a week, still at $15/hr. The husband has been promoted to store manager or higher (convenience and fast-food store chains are desperate for workers they can promote) and makes $25/hr.
(3) Their new combined income is $67,600--less than before, but still enough for a good life except in a few megalopolises. This is a completely realistic scenario, and not even demanding (the husband could easily continue to work 48 hrs a week). And it's been done with jobs at convenience stores.
(4) If you come up with places where the starting wages are lower, they're highly likely to be in poor states where the cost of living is lower. It's still a realistic scenario. Making enough money to support a family is easy in the United State if you're willing to work. Easier than it was in the fabled 1950s.
This is total BS and this person has never had to live on a low wage. That $15/hr becomes $10/hr after taxes and health insurance (of which an increasingly small portion is given back to you in services), then rent takes another $7.50 off ($1200/mo) leaving you with $2.50/hr to live. That's $400/month for gas, groceries, savings, and entertainment/shopping.
With a single basket of groceries frequently pushing $65-80 with inflation, you really only have about $100 left max for everything else.
This whole scheme is meant to force you to use consumer credit services. Ones that will compound your shortfall in interest making you a permanent debt slave to the credit agencies.
If you removed credit and reduced taxes (by actually using them to provide cheap/free services that reduce other financial burdens) you'd have a flourishing consumer spending market. However, direct wage expenditure is significantly less valuable than credit expenditure to financial institutions. They can leverage and trade consumer credit debt as an asset. They can't trade debit spending.