She doesn't represent 80% of what the left wants in the slightest. I don't recall the left being big into the Iraq War, TPP, etc.
And you're still forgetting the fundamental point here. Like me, these people
aren't Democrats. They aren't part of the same power structure. They want a candidate that closely fits their left-wing values which are far removed from somebody like Tim Kaine.
As this article from today was discussing, a lot of them aren't regular voters and certainly aren't lifelong members of the party. These are not votes that Clinton can easily flip.
Why Clinton Might Have A Tough Time Flipping The Sanders Holdouts | FiveThirtyEight
I mean, what you're fundamentally arguing is if a Libertarian candidate ran for the Republican nomination and barely lost, you'd feel that all those voters now need to fall in line with the Republican. But on a logical level, that doesn't make any sense because they aren't even remotely near each other on the political spectrum. Since when are socialism and free market capitalism the same? In the rest of the world, we have Socialist parties, some of which often topple the center-left groups that used to hold a stranglehold on power. And there's a wide chasm between what those sort of parties want...basically, the lack of choice in a two party system is what's generating a lot of this anger on both sides. There's significant enough political differences that there should be a major far left American party, etc.