There's two votes scenarios for me:
Hillary: Maintain the status quo and continue the slow political decay.
Trump: Gamble on either a very good president who is just full of shit right now to get elected, or a very bad president who probably lasts 4 terms and wakes up both parties and the 1%.
We've been doing the Wall Street money thing for a while. I'm ready to vote for change away from special interests. If a candidate is not taking corporate money, I am placing them a higher priority over other candidates. The long-view on Clinton is terrible.
Here's a list of things the Clinton administration did that I consider particularly odious in long-term effects:
The point is not to make the same mistake twice and elect a Clinton into office.
Bush, Clinton, Bush, Obama (!), Clinton... when your presidential lineup looks like the passing of royal names, you might be an oligarchy.
So I can understand how you think it's irrational, but I feel it's based strongly in historical evidence, voting and performance records, and current campaign funding.
Plus Clinton absolutely should be indicted for those emails. I'm not really interested in electing a felon into the Whitehouse.
Clinton is a non-option for me. I'm actually a progressive who is so far anti-Hillary that I'm willing to vote to put the country through a risky Trump presidency (who knows, he could surprise us) than continue to enable those manipulating the status quo.