Sometime, somewhere in the beginnings of the 2024 presidential campaign by the Democrats, they've decided what strategy to use in order to win. Instead of putting forward policies that poll best and with bipartisan support, they've decided on using the fact that the other option is way worse, as the primary reason to vote for them. Democrats also tried copying and compromising with many of Trump's policies and wording regarding border control and the economy, in order to win over some Republicans or “centrists”. They've removed medicare for all, opposition to torture, and support for trans healthcare from the democratic platform, and hence lost large chunks of their base in critical regions.
In order for no one to make the Democrats themselves accountable for this loss, they've also decided on an old reliable scapegoat: third party voters. Instead of earning these people's votes by not doing the aforementioned reforms to their policies, the strategy was to guilt trip these people into voting for them with “lesser evil” arguments. That doesn't work. It didn't work with Reagan, it doesn't work today. The lesser evil would be for Democrats to no longer listen to their corporate sponsors, and do what they always knew polls best.
They've decided to trade-off chances of winning this election, for appealing to big businesses and their lobbyism. That decision-making is what we should blame the lost election on. By blaming some minority group or some third party voters, you're playing into the game, make individuals responsible for structural issues, and hence ensuring that the Democrats won't change strategy for the next election.