There's probably a lot of truth in what you say. But, the economy abhors a vacuum, and there will either be "something" that starts up, or in some cases not and those towns may die. The dead towns will have a complicated story that in many cases will probably include the death of local businesses by Walmart.
If I ran 7/11 or Shell, I might be thinking about how to put in gas 'n goes with a somewhat larger retail footprint, a larger percentage of life groceries than potato chips. That would have the backing of a large corp, so the first yearly lack of profit wouldn't kill mom and pop's retirement, and comes with knowledge of running the outlet and managing supply lines.
Bonus, you're gonna gas up before you make that three hour grocery run, maybe what they have at the gas station is good enough, or reduces the number of trips you need to make.