So they're actually flipping houses (Capital) with the trades (Labor) being a means to make it happen.
They were correctly taught by someone, likely their fathers, that it's an economic system based on debt and taxes, and Capital can benefit from both. They didn't learn that in government indoctrination centers also known as publik skool.
We have a large number of post WW2 homes here because of a manufacturing plant in town. These are all prime flippers and can be bought cheap, usually from estates.