In the movie, John says there are some places in the far east where they pay the doctors when they are healthy and when they're sick they don't pay and that "we got it ass backwards here"
I see what he's trying to say, they are not paying for "sick" whereas they are paying for "healthy" but that's not the way it should be looked at. Because that's like saying "I should pay my mechanic when my car is running fine but when I need to bring my car in, I shouldn't pay." (Sidenote: you may say that could be like a "pre-payment" system but the logistics still wouldn't be efficient because who is to say how much repairs are going to be until the car is actually brought in? And how much should be paid when the car is running fine? When would payments need to be made? It's more efficient to pay at the time services are needed and can be determined)
If you are sick, you're not paying to be sick, you are paying someone for their time and service to make you better. And when you're healthy, you don't need that service and therefore won't pay.