The only conclusion you can make at this point is that Bernie genuinely believes Biden is doing a good job. He has nothing left to gain from sucking up to the Democratic party anymore. He is at the apex of his political career, and is probably in his final term in the senate.
If it was possible for him to win the primary, if it was possible that he could have made it past all the bullshit, then the reason he lost is because he is a fucking liberal who thought his opposition's platform was reasonable. This is why he failed to draw distinctions between himself and Biden, and it's why people who supported M4A voted mostly for Joe Biden on Super Tuesday.
It's like watching someone in an abusive relationship or something.
Stop Bernie, you can't fix him.
Stop Bernie, you can’t fix him.
He's not trying to fix him. Why are people still in denial that Bernie is a liberal?