The ones on the left that hate her hate her because she isn't Bernie, she doesn't want UHC, she isn't progressive enough.
I know Clinton wants to call herself a progressive and in many aspects she is but I think people look at it like this: There's two kinds of progressives,(any politician really) one who will go out and risk their neck championing a cause and one who'll wait for it to become acceptable and sign it, Hillary's going to be the latter. People on the left deriding Clinton are likely the same people upset with Obama because they bought into the idea of change and assumed that he was going to do all this shit that he never really said. Sanders was cool with them because he said he'd do it. Now truthfully, Sanders couldn't do it but he stuck his neck out there. That's what people want, someone to champion progressive causes not just let them pass once they're acceptable. Hillary'd call it pragmatism, I disagree to an extent. I think you can be a champion and also be pragmatic and settle for less in a good compromise, I'd say she's really just playing it safe. Which makes progressive an odd, label, are you a progressive if you support something once it's politically popular to do so? I dunno. In either case she won't obstruct progressive causes I just don't see her fighting for them either.
What I wish most progressive voters would start to realize though is those people aren't exactly enemies to the movement. They're waiting for you to place something workable and passable on their desk, that's more than most!
Though I will give Hillary credit for staking out a position against gun manufacturers. 'Course whether she can follow through with it is another matter entirely but she's on the record saying she'd like them to be liable for gun deaths. For the first time now all the right wingers I know claiming the President wants to take away their guns will actually have a point!
People on the right hate her as much as they hate the Devil or Communism.
I'm going to slightly disagree with you. Firstly, Hillary absolutely is in favor of Universal Healthcare. She has the lumps to prove it. Now, she disagrees with Sander's approach, as do I. But to say that she's not in favor of it isn't really accurate.
The difference between Bernie Sanders and Hillary does come down to something you said about sticking your neck out. Hillary has learned throughout her career, that sometimes when you stick your neck out too far, it just ends up getting your head lobed off. Bernie, being an Independent back bencher for most of his career(and I don't say that with shade, I mean it in the nicest way possible, honestly) doesn't have that problem. He can yell at clouds and give speeches to empty rooms all day, and it's perfectly fine. That's not what a President does, though. That's what an ideologue does. (Again, I don't mean that in a completely negative sense.)
I'm not saying that it's not admirable. I'm not saying it's not justifiable. I'm not saying it's not alluring to some. But, a President is about getting results. Bernie has a lot of ideas (some are good, some are downright awful) but, in his 30 years of public service, he's done almost nothing to get them passed. (Again, I'm not throwing shade on him, nor am I trying to pile on the guy because this thing is over anyway).
Should a President be inspirational and aspirational? Absolutely. But, I don't think that is the sole defining factor of liberalism or progressiveness. Especially since I, and a lot of other people, find Hillary to be both of those things.
Now, I agree with you that we liberals often let the perfect become the enemy of the good. We've always had that problem, as does the right. It's just human nature.