The problem wasn't that Harris courted Cheney.
It was that she stared down a whole population of Americans who got poorer under Biden and said publicly: "I wouldn't do anything differently." It also didn't help that she told all of these increasingly impoverished people to just be joyful for three months of her campaign before even addressing anything policy-wise.
But, at the end of the day, if you want people's votes, you're going to have to figure out how to display some level of empathy, because openly hating everyone who votes differently hasn't worked to win them over to your side.