As I mentioned that living minimum wage can and should be adjusted by region. So in CA where cost of living is higher than other states it would be higher than that $21/hr that I mentioned for the federal level. I think I read recently that according the Bureau of Economic Analysis, the average cost of living in CA is ~$55K/yr, so then the average minimum living wage would be ~$26 in CA.
Also we're starting to get into some philosophical territory here. However with that said, while one can and certainly should try to better themselves we don't know everyone's situation, passions, or desires. Its easy to say that someone should gain skills or whatever, but some circumstances don't allow for that type of situation. For example what about a single working mother who already has to work two jobs in order to just to afford to have some place to live. She can't afford time nor the cost to go to school in order to better herself and also afford daycare, housing, food, etc.
But let's say someone has a passion to make churros at Disneyland that also shouldn't preclude them from making enough to survive. Doesn't mean they buy a house, or whatever. But at least enough to survive in the state they live without going into severe debt, poverty, or live in their car.
We're the richest nation in the world, we can and should be wanting to help pull up those who make the least and we certainly can afford it. As the saying goes, "a rising tide lifts all boats". As we help those who makes the least it helps us all.