The late Harvey Butchart was a determined explorer of the Grand Canyon, logging some 12,000 miles and 1,000 days, summiting its peaks and finding new ways to get from the rim to the river. He did it wearing K-Mart boots and backpacks. He wouldn't know what to do in an REI.
On principal I abhor Walmart for the many reasons already cited. But let us keep it real. Consumerism is a disease, yet it has lifted many millions out of poverty - at a very high cost to the planet. I visit and hike the Grand Canyon several times a year. It is a ten hour drive each time. I know that the relative merits of my frugal miserly ways of making my own gear and babying it to last me a lifetime (and buying local) hardly makes up for my transportation to get me to trailheads.