In a free market they don't have to respect shit. Normal people actually have the power to walk away from them. If they don't may money, they aren't big corporations any more. They use government controls, tax breaks, and subsidies to maintain money and control. They idea of anarcho capitalism is that I have the power to make a good life for me because no one has the power to control me.
Discussion
They have the power, but not every consumer can be a fully informed one. The free market isn't that great at that sort of self regulation for just that reason, punishing businesses at the cash register for poor behavior requires knowledge of that poor behavior be spread across huge chunks of the market. Yes, there are cases where this happens, but companies get away with poor behavior purely due to public ignorance way more often than we'd be comfortable with if we knew.