That's a very hostile way to describe working a warehouse job.
Offering someone a job is not asking them to break their back. Working for an employer has nothing to do with the extravagantly wealthy. All companies need employees, and companies are valuable because they serve their customers. You could equally say "break their back so random Internet consumers get their products", or "Burger King / WalMart employees break their backs so you get a cheap cheeseburger / grocery product".
Working a job tends to make people better off, and offering someone a job they didn't have before is giving them a new option. We can wish for a world where even better jobs were available, but wishing doesn't make it so. It's strictly better for the homeless to have one more job opportunity, than one fewer.
You can wish there were even better opportunities, but are you prepared to provide them yourself? Or is this your position: "I'm not going to do anything about it myself, but I'm going to criticize those who do something positive, even if it's just providing a low value opportunity. Someone should provide a better opportunity than that, but I won't be the one to do it."
By demonizing companies that offer jobs to poor people or the homeless, you're committing the fallacy called the Copenhagen Interpreation of Ethics. http://blog.jaibot.com/the-copenhagen-interpretation-of-ethi...