Not surprised by this at all, unfortunately.
To expect a man of his age to suddenly change is pretty foolish. I mean, I was a Bernie supporter in 2016 and 2020 (and well before that, TBH), but I recognized that Bernie was set in his ways and while this frustrated me, I also figured it was part of the package and to be expected when voting for someone in that age bracket.
Not that it's impossible, or that there can't be continued growth, of course.
But Biden's always spoken in a way that shows how highly he thinks of himself---both he and Trump use the phrase "I'm the one who..."--as though they are such a gift to the rest of us little people.
And you're right, his record is nothing to be proud of.
Anyway, I made all of these comments before the election and will continue to make them---Biden and the Democratic Party have joined the Republican Party as being for anyone but us, the People.
WE are going to have to figure out a way to either change that, or maybe get a new party going altogether.