Did the DNC manipulate the vote? Did they override the primary results? Or did the majority of primary voters support Clinton?
Most of the people who bitch and moan about it didn't actually bother to vote in the primary. I voted for Bernie. I was out-voted and instead of crying and refusing to vote I voted for Clinton in the general election because Trump was too dangerous while a bunch of Bernie "supporters" didn't.
Then they got possy with Harris over her objectively-less-bad position on Israel than Trump's, allowing him to win again.
Show up to the primaries to move the party left. But also show up the the general if you lose, because the reality is twice now people's demand of perfection from the Dems has resulted in Trump being president.