Eichenwald? During the campaign, he mostly came across as a… mild-mannered reporter. Most of what he wrote was investigative stuff having to do with Trump's businesses. For that, he received a lot of anti-Semitic hate mail. Odd, because he's actually Episcopalian.
Naturally that pissed him off. And in the present article, he's not pissed off at Bernie, whom he doesn't dislike. He's pissed off at Bernie supporters who're now whining about Trump, but actually didn't vote at all, or voted for Stein.