First of all, I refuse to subscribe to the absurd notion that supporting candidates who would be considered at best centrist in most of the rest of the developed world is criteria for branding someone 'far left' regardless of political context. The American political frame of reference is wrong and obviously skewed; that's precisely part of the problem.
Second, the corruption Hillary engaged in is the sort that has become normalized and mundane: legal, and fraught with plausible deniability, but present, unethical and prominent nonetheless.
Taking massive paychecks from corporations to do trite speeches, and having the coffers of your charity fill roughly in proportion to the influence you have to offer, with a campaign propelled by and largely dependent on megadonor funding is bad enough certainly. Clinton of course went further: bailing out the DNC Obama vampirized in return for great power over the gatekeeper institution that is fraught with obvious, material and serious conflicts of interest; openly declaring her duplicity in the favour of Wall Street execs behind presumably closed doors by reassuring them she had a 'public and a private position' after a lengthy period of coddling them, saying they're misunderstood and otherwise blowing sunshine up their ass.
Beyond that, and above all else, her policies were garbage compared to Sanders in our view, and of those we might've liked, we couldn't really trust her to follow through on them, especially not versus Bernie. On that alone, she was a no sell; the majority of us would hold our noses to vote for her in the general, but certainly not in the primary.
Lastly, we have Trump as president primarily because Clinton was one of the worst candidates the Dems have ever fielded and her campaign was woefully inept: she was despised almost on par with Trump, she exuded an aura of anti-charisma, inauthenticity and repugnance, her vision was muted, uninspiring and scant, and she neglected key states despite warnings from Sander's campaign after it had begun to work with her. Under her watch, the so-called 'blue wall' that ultimately cost her the election flipped, because she failed to speak to the concerns of those voters in any direct and substantive way, and took their support for granted. To lay the blame at the feet of the 'far left' when Sanders' supporters were more loyal to the party than Clinton's were in 2008, and despite the fact that the majority of those that did abstain or flip didn't have strong ties to the Dem party in the first place, speaks to either a wholesale lack of understanding of what actually occurred then or a blatant and highly partisan willful ignorance.
As per above, there are many legitimate criticisms to be had regarding Clinton; unlike the right, we despise her on the basis of substance and factual flaws and saw in Bernie a vastly better candidate, regardless of whether or not you choose to acknowledge that.