Two things:
Leftists did vote for Clinton. (You'll recall she got more votes.) That is despite the fact that she was a piece-of-shit candidate that we didn't want, and didn't win the primary.
Harris was just plain stupidity. You can't look poor people in the eye for three months and tell them you won't change anything and still claim to be decent, much less a legitimate presidential candidate.
Respectfully, you're being very unreasonable. You don't get to punch the voters in the face and then whine that you broke your hand.