The fuck??? Why would home depot discoursge this??? Get a bunch of day laborers outside, who aren't affiliated with your company, and it's only GOOD news for your profits.
Consider this. A new home owner wants to refurbish their kitchen. So the guy goes down to home depot to get some materials. But he also knows there's some day laborers outside.
So now he's bought the materials from you, hired the labor from guys hanging around outside your store, and no matter what happens next, you made a sale because you're known for having day laborers outside.
Plus, even if they do a shitty job, the home owner has no recoarse against you. He can't sue YOU for shoddy worksmanship. You never hired these guys. All you did was sell the materials, and the materials are fine. It's the installation that was subpar.
And plus, it's not like home depot sells a seperate service of installation anyways. So they don't lose money, they gain sales, and have no legal obligation, and benefit from having an installation team that you don't pay, and aren't legally responsible for in any way.