Clinton looks unattractive to a lot of left-leaning people because they think the left is in a stronger position than it has been in a long time and so the Democrats can afford to have a candidate to the left of Reagan. If you're looking at things that way, Hillary is a relic of a very bad few decades and you want someone less pragmatic and more of an idealist now that you don't feel like you're on the retreat. If your glasses are more jade than rose you remember that Obama isn't far to the left of Reagan and the Democrats still had to fight tooth and claw to get anything not completely mundane done for the past 8 years. Give me the compromised, cynical, professional lesser evil. Bernie bringing socialism back into the Overton window is great, but it's not yet time to stop being defensive.