I generally agree, with one pretty big exception.
And also correct.
But those two things are not unrelated. In fact, they are deeply intertwined. Its kind of like saying, Trump wasn't actually in the July Trump Towers meeting with the Russians, but there was a culture of colluding with Russians...but we can't really hold Donald responsible because he wasn't in that one meeting.
I definitely agree with this, and is one of the chief criticisms I have of Bernie. He has a pretty lengthy track record of just brushing aside any and all criticisms of his behavior, past and present. And he largely got away with it in 2016,. because the Clinton campaign refused to drop oppo research on him or push to make him be held accountable.
Bernie doesn't like being criticized, and unfortunately for him, that's a big part of this particular job.