Rogan made him his charity case after the MMA community told Rogan that he was too mean to Brendan. Taking that verbal beating was the single greatest thing to happen to the Shaub family line in its' history. Rogan was still in the peak of his pseudo intellectual "just be a good person, mannn" phase and made Brendan his personal lap dog for years because of it.
Part of being Rogan's dog is that you have to pretend like comedy is some deep, edgy subculture of truth-tellers, so poor Brendan had to go along with it to please Master ("Yeah man. He killed! Oh man! Like whaaat?" etc).
Now that Brendan has milked as much as he can from that particular angle of the Rogan Cow, it's time to move on and focus on more mainstream endorsements/ventures.
Shaub is an absolute goof but he either knows how to play the game well or his Jewish PR firm does. Once you get your hooks in the Rogan gravy train it's hard to fuck it up.