I dunno about Walmart being hard to get to. Most that I have seen are pretty cleverly located. In some cases, they just had good vision or something because it seems like where Walmart plants, a business district grows up around them.
In our city, there USED to be a vibrant downtown stacked with small businesses. Then, some brilliant minds decided to tear it down in the 70s/80s and put up a mall. The mall died in the late 90's and the suburbs moved the vibrancy from downtown to the outskirts. Now, the big box stores are a lot more convenient to get to than the old downtown for most of the cities families.