Honest question: Why work at Wal Mart then? Are you being forced to? Is anyone? I’m serious about this. Please don’t reply with something aggressive and mean.
Because sometimes people can't find anything better, for a number of reasons. Could be geography, could be education...
You asked what stops people from moving to an area with better options, or creating an online business, or trying to invent a product... well, a lot of people do just that, and they end up homeless because their attempts at a better life fail. For every person who makes it because they moved to a better location, or started a business, or invented something, there are hundreds (if not thousands) of people who don't make it. And that they fail doesn't mean they didn't work hard enough, or they weren't smart enough... sometimes life just beats you.