I think this is 100% on point. Both Ian and H3 had started at roughly the same time, and earned their fame doing "edgy comedy". As time went by, everyone in that circle started to go more mainstream to better fit in the post-Adpocalypce YouTube. Almost everyone from that circle has maintained their popularity and even grown, despite a radical change in image. Everyone except Ian.
Even Filthy Frank managed to launch a successful music career. Everyone was able move on from the past except for Iddubz. In his understanding, he did everything the same as the others, but despite his apology tours, disowning his fans, reinventing his online persona, he's still the Nigger-Faggot Guy, and a sissy cuck on top of that. H3H3 has a CEO of YouTube on speed-dial, a successful podcast, a clothing brand and a stable enough marriage to produce children. Iddubz has a dead channel and a bitch of a wife.
So I think Iddubz got so spiteful through the years that he jumped on the first opportunity to ruin H3.