That sounds like a shaky argument to me. The average family CAN live on much less that that (living proof). Often the biggest problem for people trying to make ends meet is DEBT. So many people REFUSE to live within their means and instead go charge up the credit card and take out loans to purchase things they don't need and will not help them increase their income. If more individuals and families would decide to act responsibly and only buy what they can afford, so much financial hardship would disappear.
That said, I can't see how $22 per hour could accurately be the bare-minimum wage. Many people who earn much less live comfortably because they know how to control their spending and saving.