The big difference being everyone rejected has paid into the system their entire lives.
Healthcare can't be considered a right if their is rationing going on... and at least most people rejected for treatment in the USA aren't paying for it.
Now if we could come up with a universal healthcare plan that didn't introduce rationing, but also kept the free spirit that drives technological advances foward.
THAT would be something to have.
For example by backing it with a government program that would MAKE the government money. Like life insurance or something.