Haven't seen the movie myself, however I'm sure it's nothing terribly shocking that I didn't already know. Home Depot, Lowes, Target, all are similar types of corporations that push huge volumes and can squeeze out locals. It's really an american way of life, it's how places like IKEA thrive, mediocre products at an affordable price.
I have only been to a walmart store once, a few months ago, I was expecting some type of "special" experience, see ultra low prices on everything, etc.. meh.. it reminded me of KMart, only bigger, and I can honestly say I'm ok with the fact walmart doesn't have any stores in this area, it's bad enough with Target.