The problem there is that the subsidy money has to come from somewhere, and the longer that tax gets pushed back, the more we have to do other shenanigans to come up with the money: borrow more, raise taxes elsewhere, etc. As it is, the subsidies don't really help folks as much as was planned, and even with the subsidies, the costs are rising quickly. It's a runaway train at this point: costs rise, making the subsidies insufficient, so the politically expedient thing to do is to expand the subsidies, which means that taxes must rise to pay for them.