People act like everything done is so permanent. All it takes is one war and none of this stuff matters.
If you don't like their business practices, see if you can join any movements against them or start one.
Become a lawyer and instate legislation against such business practices.
The current economic system is merely an abstracted/evolved form of handing someone a shiny rock for a chicken. The downside is that since this new form has no physical backing, the concept of wealth and value is nothing more than a shared idea between individuals in society taught that this is the way things are.
Just over a hundred years ago and you could still easily buy things with gold.
While its cool the way the systems have come together to allow for rapid development, it will come at the price of local businesses like that. (unless of course such business practices prove to be fatal in themselves. As specialization almost always seems to win out over generalization when observing socio-economical systems, Walmart versus specific retailers in this case, walmart may not win. Then again, though, the power of compounded wealth is quite something to behold, and even if they did today start loosing steam, walmart will likely be around for a long time)
I predict a different economy emerging with multiple specialized markets for certain products. Perhaps still relying on our nothing-backed dollar, but I hope a better system can be worked out.