With the spotty selection Wal Mart carries in their music dept. if they put a local store out of business, then the local store already had problems. Wal Mart coexists in several markets with niche stores that either duplicate Wal Mart departments or complement them. Music stores are a perfect example, video is another. Wal Mart's prices are great if they have it. But they also dont carry "adult" versions of albums with questionable lyrics, and the movies may not be the best version available.
To simply say Wal Mart puts locals out of business is a stretch, at best.