That's because there are no easy fixes. Paul Krugman (NY Times columnist) wrote a good summary many years ago about the interlocking components of ACA, which he reproduced a few days ago on his blog at the paper (on Jan 10, 2017). Here's the 2010 language he quoted in the recent blogpost:
Start with the proposition that we don’t want our fellow citizens denied coverage because of preexisting conditions — which is a very popular position, so much so that even conservatives generally share it, or at least pretend to. So why not just impose community rating — no discrimination based on medical history? Well, the answer, backed up by lots of real-world experience, is that this leads to an adverse-selection death spiral: healthy people choose to go uninsured until they get sick, leading to a poor risk pool, leading to high premiums, leading even more healthy people dropping out.
So you have to back community rating up with an individual mandate: people must be required to purchase insurance even if they don’t currently think they need it. But what if they can’t afford insurance? Well, you have to have subsidies that cover part of premiums for lower-income Americans. In short, you end up with the health care bill that’s about to get enacted.
There’s hardly anything arbitrary about the structure: once the decision was made to rely on private insurers rather than a single-payer system — and look, single-payer wasn’t going to happen — it had to be more or less what we’re getting. It wasn’t about ideology, or greediness, it was about making the thing work.