ACA single payer resistance concept

The insurance industry plays a major role in the American health care system and absorbs a significant portion of the health care dollar. A single payer system, whether it is a private company or the US government, would eliminate the complex insurance paperwork burden and free substantial funds that could be diverted to support care for the under-served.  In ACA debates, a “public option” was defeated by lobbyists. Identify some reasons why resistance to a single-payer concept, used in every other developed country, has continued in the U.S.