Nobody deep in the blue is going to stop voting Democrat over these things, stop pretending that's the issue. The problem is that the people necessary for Biden to win are not your typical blue voter. They might dislike Donald Trump as well, but for whatever myriad of reasons don't rule him out as a person they will vote for. They exists - if they didn't there would be a critical mass of voters to win and the republican party would have been dead or you'd never have a Democrat as a president.

Most likely - they feel disenfranchised by both the Democrats and Republicans because their concerns aren't being heard. And by not taking their concerns at least somewhat seriously yet again, you might piss enough of them off to lose the majority. And this attitude really isn't helping in salvaging their trust. Telling someone they're going to vote for a candidate they don't trust or want whether they like it or not is NEVER a good slogan to run a campaign by. It only works on people that are well informed about what's at stake behind the scenes.

What's the problem with just being honest with each other for once. A better candidate more people could stand behind is what democracy demands. America's two party system has always created unpopular choices, and everyone normally agrees with that. But when one side sinks to an extreme, suddenly it made the perfect choice on the opposite side? Why are people so afraid to open the possibility to unite behind a more coherent and capable Democrat backed by the same cabinet, who can dunk on Trump's lies and rally people with a plan to actually make sure all the terrible things that happened get undone?

Saying you don't want to vote for Biden isn't an endorsement to vote for Trump, voting third party, or not voting at all. It's a plea to find something similar, but better, that more people can stand behind.