Pretty much. He ran in the primaries, they were mad at him, he lost his committee memberships and is no longer seeking re-election to congress, he speculates that this attitude from within the party is why no one else seriously ran against Biden.
I'm not alleging a grand conspiracy or anything. It just seems like internal party politics and personal incentives led to the democratic party ultimately ending up with a nominee that people aren't excited about (who I will vote for anyway).
And Dean Phillips did run in the primary, so again, nobody stopped him. Biden defeated him.