Because the entire healthcare industry is corrupt as hell already.
It's not corrupted, it's provided by private companies in a capitalist system, and, to be more realistic, in the USA it's in an unchecked capitalist system.
Let's talk a little bit about politic: we live in a capitalist world. The basis and only goal of the capitalism is to earn as much money as possible, without any consideration for all other parameters and (collateral) damages.
Health, healthcare, private clinics are only a business, and like all other businesses it's only to make money, much money, more money. And health is a juicy business, because everybody becomes sick at one time of his life, so it's a business with (almost) 100% of the population being potential customers.
Meaning that a private healthcare company as absolutely no interest in your health, the company exists only to make a big pile of money in a juicy business... with, like any other company, a bunch of vultures and parasites called "shareholders" asking/telling/ordering the CEO to make even more money. And like any other insurance system, the only way to make more money is to charge the customers the most possible (and even more) and to reimburse the less possible (and even less with all the possible means to avoid paying) to get higher profits : so a huge part of the money collected goes directly into the pockets of the shareholders and only a small part is used to pay the medecines and the hospitals/clinics/MDs.
I think it would be even worse if it was made into a federal program of sorts.
In the french system, the "Sécurité Sociale" is not in the pocket of greedy shareholders, but is handled by the government, it's a public service, provided to the people, a service which is not intended to make profits: so almost* all the money that comes in (from the mandatory** subscriptions, collected from every companies and every working people) goes out to pay the medecines, the hospitals, the clinics the MDs, etc. to treat and cure everybody: in this system, everybody pays for everybody. And as everybody needs health care one day or another, (I think that) it is somehow quite fair.
* almost, because as a public service, people who work in are civil servant and are paid by the state and by a small part of the collected money
** that's the problem: collection is mandatory... that's the problem and that's the basis of the debate about (quoting
kansasquaker) "
Who [you believe] is ultimately responsible for the wellbeing of an individual - is it the individual himself or the society of which he is a part?" The french government clearly considers that he is ultimately responsible of the health of the French... but not all the French agree!!!