Those individual mom and pop stores can't survive because 1) they charge more for the same product 2) they don't offer anything new that big chain stores don't.
I don't see why they should not be out of business. Of course they can't compete with large chain stores in cost, but come on, at least provide something big stores don't. Otherwise, what's the point of shopping there, just to "support local business"? that's absurd.
Yes, it is easy to blame large chain stores for squeezing small business out of business. However, have we thought about what those small business have done to remain competitive? I was in New York this weekend, and there is this hugely successful hamburger place where you need to line up for at least 30 minutes at 2pm, just to get a burger. These small business survived and thrived despite the existance of McDonalds and Burger Kings, didn't they? because they created a competitive advantage where corporations with 3000 stores don't. It is in the heart of Manhattan and God knows how many hamburger places are in there competing.
In the end, you can't expect to survive when you offer completely homogenous products at 20-30% price premium. It is quite fair. It is backward to think "how sad this corner store has to close, why don't local people support it?". Why should anyone "support" it anyway?