Who's going to employ poor people once you destroy the businesses who employ poor people?
The question is not who employes them, the question is who pays for their living expenses. If companies don't pay a living wage, then that's you and me.
Society is not a suicide pact.
These people are paid so little because their labor is worth so little. Making them unemployable doesn't make their labor worth any more than it currently is.
Then it shouldn't really matter if they're employed or not, now should it? After all, if their labor is worth little, then the economy is little affected if it's removed, right?
We will see not only jobs moved to other parts of the world, but the automation as well. Call it "race to the bottom", "exporting the pollution", whatever, but it remains that a growing amount of valuable economic activity has been chased out of the developed world and it's not coming back.
What valuable economic activity would that be? Surely you aren't referring to activities so unprofitable that paying minimum wage for them is a "punishment"?
Manufacture for example. And Walmart and McDonald's do have valid business models and very useful services that depend on low wages. They can achieve that by automation or by paying people what they're worth.
You can't have it both ways. Either these people's labor is valuable, or it is not. If it is, then pay them for it. If it's not, then it doesn't matter whether they're employed or not, because they're poor either way and the economy is by definition unaffected by losing low-value labour; the only ones affected is McDonald's and Wal-Mart who'll have to shell out for automation rather than continue having their profits subsidized by having me pay their workforce. Which one is it?