During an episode of the "Taggart and Torrens" podcast (starring Torrens himself, as well as his friend and fellow comedian Jeremy Taggart), Torrens revealed that his decision to leave the series revolved around the fact that he had outgrown the character, both physically and mentally. Torrens joked about how hard it was to keep playing a gangster as he entered his 40s, and went on that by the time Season 11 came around, there really wasn't a lot left to tell when it came to J-Roc's character. We had watched him grow from an unintelligible buffoon into a (somewhat) responsible husband and father, and at a certain point there was nowhere new that J-Roc's story could go.
Torrens felt that it was better to move on and explore other roles rather than to continue on with a character that couldn't break any new ground, and said that he was still very happy that he left the show when he did. That said, Torrens also reiterated how grateful he was for the fans of the series and for how beloved the character was. Now that the series is switching to animation, perhaps Torrens' age won't be so much of a problem, and he could return in a small cameo somewhere down the road.