Easy to understand why:
A lot of people will lose the ability to afford health insurance without the government subsidies. They will go without medical and hospital insurance.
They'll still get sick. They show up at ERs at hospitals. They'll still be treated.
The hospitals take a hit financially. And someone has to make up the lost revenues.
And the hospitals and the doctors will have to raise their fees. And in turn, so will insurance policies for NON-ACA policy holders.
And that means you and me.
Don't think that Medicare won't be affected, b/c it will. Same thing costing more money. It has to come from somewhere.
By letting the ACA subsidies expire, all of us are now engaged in "medical Kerplunk". Please see video. By pulling out the "sticks" of the subsidies, eventually, KERPLUNK!