he discontinued it because RG had gradually become 95% splices and remixes since The Return. In the golden age of TCR from '08-'12, splices and remixes were only like 50-60% of RG, and the rest of the calls were character calls, trash-talking, and banter. Ghost always preferred that RG exist as an interactive opportunity for verbal sparring with characters and trolls, since he believed the trolls ought to face his banter if they wanted to dish it out on air, whereas splice/remix calls don't give him as much material to work with and somewhat insulate the more cowardly trolls from his ripostes.
RG in the old days was to a huge extent defined by the ongoing battle of wits and bantz between Ghost and the big troll characters, almost like a kind of sitcom in terms of the extensive storyline and evolving relationship between Ghost and the supporting cast of characters. Since The Return, though, only Tub Guy remained of the classic troll characters, and all his calls are "scripted" and fairly repetitive anyway. There were a worthy handful of new troll characters like the African Booty Scratcher and Germit the Frog who stepped in to fill the void, but there were not enough of them and they did not call in with the same frequency as the big characters in the old day.