Consider that they feel the same way about democrats as you feel about them. Also consider that they are always told that third party votes are ineffective. At that point, they might decide not to vote.
Also, in before I'm accused of being a Trump shill, that I won't vote, or that Harris is still better than Trump. I know she is, but she also is abetting genocide and I'm okay with that being a hard line for me when I'm in a blue state. Dunno who I'm voting for president between her, third party, or leaving it blank, but I'll definitely still be voting for other races.
It's both. Yeah, Americans continue to be unmasked as racist and all, but the DNC absolutely shat the bed here as well.