I have something of a strange relationship with liberal defenders of the Affordable Care Act. I actually think the argument that a more progressive reform that cut off for-profit health insurance at the knees would never have passed the Senate is basically correct. Any deal that was reached was going to have to ensure that the health inscos got theirs first. And this is where Obama's defenders usually leave it. Their man is off the hook, having defeated the pretending challenge of "firebaggers" and "emoprogs."
But, let's take a look at two possible statements concerning the ACA and its discontents, and the Obama presidency in general
1) Obama is a sellout who has turned out to be far less liberal than people expected/desired. (the "emoprog" position)
2) Obama's personal beliefs are irrelevant, because the political system is wholly owned by wealthy interests who can water down popular policy ideas (such as a public option or single payer HCR), making them less popular with the public but more palatable to the political class.
Which of these would present the bigger problem? The first would be an annoyance, but presumably correctable, which is, one assumes, why Obama's critics tend to focus on it. It gives them hope, if you will, that eventually an election will produce someone more in tune with their own beliefs and progressive outcomes will soon follow. Obama's defenders typically rebut this by pointing to the second, usually without much consideration of what this represents: a shambolic political system in crisis, increasingly unable to do the cursory job of "representation" on which liberal democracy so prides itself. But it's not Obama's fault so, yay, kids!