As a diagnosis of why people are mad, I think you can’t do much better than this:
I think people are pissed right now less at the fact that they didn’t get what they wanted, and more at the fact that they feel like their people didn’t really fight for it. Leaders don’t always get what they want. But people recognize when true leaders at least give it a shot. And people judge that leadership by what they say in public and how hard they see them publicly pushing for it. Closed door negotiations don’t count.
They wanted to see Obama push the public option and say that it was crucial, important part. His broad outlines of “cuts the deficit, improves coverage” is too bland and not something people can rally around, and he gives the impression that he’s ceding power and leadership to a less capable bunch in the legislative branch.
They wanted to see news stories about how “staffers close to the majority leader” say that chaimanships and other perks were on the line for any Democrat who talked about filibustering this crucial bill.
They wanted to see congressional leadership and the president campaign hard for an “up or down vote on healthcare” the way the Republicans did so effectively for the judge appointments.
But none of that happened, and the things that people care about died with a whimper.
I think the problem with that stuff is that it doesn’t work, and the evidence is pretty overwhelming that the president can’t move public opinion. Just like I think the evidence is pretty overwhelming that campaign tactics don’t determine who wins presidential elections. But even though neither of those propositions is especially controversial among political scientists, both are hugely unpopular with political junkies. So people are bound to be mad about how casually the White House accepted the view that its job was to (a) discern what Nelson/Lieberman would vote for and then (b) sell everyone to the left of Nelson/Lieberman on voting for it.