This article from MSNBC discusses Walmart's foray into sourcing food from local farms. It's worth reading, especially the blind tasting of products purchased at Whole Foods vs Walmart. Walmart food came out ahead multiple times. There appears to be a genuine effort by Walmart to pursue locally sourced food and I don't think we should just blow it off.
If Walmart wants to build inside the city limits, perhaps we should consider a requirement that the store implement the locally sourced food program. It's a win-win, especially if the store is built in a food desert. The citizens get access to fresher, healthier food at a price they can afford, the city gets tax revenues, Walmart gets business, and local farms get a reliable buyer. It would be a start in the right direction.