I fail to see what the idle rich have to do with supply/demand. Vulture capitalists buying and breaking up companies is very much in line with supply/demand (in the financial markets). As are non-competes (malicious or otherwise) which directly effect the supply of skilled labor. Discrimination based on non-utility factors directly influences supply/demand and thus influence prices of all sorts of things.

Economic theory around supply & demand simply describe how economies work. It does not imply that it will lead to a better life for all. In short, the "law" of supply & demand is about price discovery and resource allocation efficiency. It has no moral or ethical component that you seem to feel it implies.