I hate Walmart because it destroyed the sense of community in thousands of towns and cities across America.
Think of all those mom-and-pop stores that closed because of Walmart. The people who ran those stores probably knew your name (if you were a regular customer or a local resident), and asked how you were doing when you came in. They may have sponsored your kid's soccer team. They ran small, friendly stores where you might actually see someone you know, and have a good conversation. Historically, shopkeepers have been part of the fabric of society: they passed along the local news, they kept an eye on the local kids, they cared about the service they provided. When small stores are crushed by Walmart, the fabric of our society is frayed. We all become a little bit less connected to each other, and we are all poorer for it.
And here's the other thing: these small mom-and-pop stores were usually owned by a middle class family in your community. Each small store usually supported at least one family at middle class standards. By contrast, Walmart mostly pays $8/hour or even less. That is WAY below what you need to live a decent life. In other words, Walmart destroyed thousands of middle class jobs (the small shopkeepers of America), and replaced them with very low wage "McJobs".