Walmart isn't the problem, it's the result. Back in the day(1910-40's) the little crossroads near me had a general/grocery store, church, 2 schools, cream plant, IHC dealer, 2 or 3 cheese plants, a hardware store/blacksmiths shop, barber. The crossroads at the other end of my road had a cheese plant, school, church, post office. They were 3.5 miles apart. After WW2 most of that closed up and people drove to town, 11 miles away. That lasted into the 60's. Then people were driving to the city 40 miles away. Lots more in the town than in the crossroads, more in the city than in the town. It's a natural progression. Improved roads mean more cars, a higher standard of living means more cars. More cars means lots more traffic. Traffic requires parking space. Who here will drive 10 miles to town for lunch and put up with having to walk 2-3 blocks from a parking lot? That didn't even work in the 30's! Today in the town near me if you want a really good pizza you two choices- one established place you either circle the block waiting for a parking spot to open or you park in the municipal parking lot "out back" and hike 100 yards. The other new place has a good sized parking lot. Guess which ones is getting a lot of business and which one has seen a decline? And for the record, the older place is pretty darn expensive for this area, even though it's good. A large 3 topping with 18 wings on the side is going to run you $35.00. The other, equally good place it's $10-11.00 less expensive. Who's going to win?
Same thing for Walmart, Lowes, Applebees, etc. Yup, they put a lot of the "mom and pops out of business. How? Same product or more products at a better price. We had a great hardware/clothing store in Ogdensburg called Hacketts. They had everything it seemed and everyone shopped there. THey put a LOT of other businesses under over the years. Over 10 years or so their prices climbed higher and higher, the store got fancier and fancier and the hardware section got smaller while the high end clothing section grew. Mind you, this is in a pretty poor neck of the woods. People can't generally afford Woolrich, Columbia, Filson, etc. $45.-75.00 Levis don't sell all that well. But they had enough doctors and professionals in the city to support them, plus this was in the 90's and jobs were easier to find, credit was easy to get and the mall was 45 miles away. Then they decided to expand to 3 or 4 stores and prices went up even higher. The final straw for me was having to pay $18.00 for a 4 foot x 3/4" black iron nipple! Lowes opened nearby a week later and the same nipple was $7.00! Hacketts misjudged their customer base entirely and carried the same high end products in 3 other areas that were even poorer than ours. They lost business to Lowes, Home Depot, Walmart, Fashion Bug, Peebles, etc. Hacketts was, in a way, a "mom and pop" store but like so many other mom and pops they couldn't compete with larger chains, just as the real mom and pops couldn't compete with Hacketts. Truth is most of the mom and pops that had anything like a monopoly raped the locals. There were darn few mom and pops that kept their prices as low as possible. That's why Walmart and Lowes and what not succeed, parking, prices, selection. It works both ways though- I can pay close to $10.00 a pound for nails at Lowes or go to the Amish and pay $3.00. Guess where I buy my nails?
Sorry this was so long winded but the big chains are just the result of evolution in the market, not the reason the mom and pops failed. And parking, price and selection is why main street is pretty much dead these days.