> Who's going to employ poor people once you destroy the businesses who employ poor people?
These businesses function on razor thin margins, and that's part of the problem. Part of the vast economies of scale that they command is keeping labour costs down.
If they go out of business, the huge volumes they deal in would presumably be missed. Other suppliers would step in to fill the void, only not being so large, not commanding such economy of scale. In short, having to employ more people to get the same amount of stuff done.
> They can achieve that by automation or by paying people what they're worth.
And that's the cornerstone of your argument - that some people are not worth paying enough to survive, in short, that they have so little value that they should die. This must be the case, because their income needs supplementing with government aid. If their labour was actually worth enough to let them live, they wouldn't need that support.
Oh, wait, if they died, they wouldn't be around to be a component of those "very useful services" that Wal-Mart and McDonalds provide.
Looks like the market is failing to me - if their employer didn't pay enough to maintain the fork lifts, or the fry cooker, they'd be unable to do business. But they don't pay enough to maintain the shelf stacker or the burger flipper. They only way they continue to work is because the government steps in. You wouldn't expect the government to step in to fix your milkshake machine, so why should they support your underpaid labour?
Because the governement has a moral obligation to help the needy, the only way around this is to legislate that labour is paid enough for them not to have to.