I mean, he says this and it's a good message, but from where I'm standing it does look like all the Bernie supporting crowd put all their eggs in one basket and now it didn't work out are freaking the hell out.
Doesn't help all the people who were running around saying Bernie https://twitter.com/shaun_vids/status/1248029980434595840

would win in a landslide and who over estimated how far left America would go. America is a deeply conservative country and it seems weird to me that people had this weird level of confidence in a Bernie win.
I love Bernie, I do. His policy is hands down the best of the Dems.

I just really don't get where all this confidence came from from the Bernie supporting camp that he would knock it out of the park with the media attacking him, without the support of his party and with America being so right wing generally.

There's also too many Bernie supporters online who treat him like the messiah and don't want to acknowledge ANY aspects of his messaging could have been alienating to some voters (eg calling himself socialist, abolishing private health insurance etc.)