Unsurprisingly, the decision to axe the outside produced Mike & Molly boiled down to money.
Per Deadline, the show’s ratings weren’t big enough to warrant the expensive renewal of cast contracts and license fees:
I hear producing studio Warner Bros TV early this season approached CBS about possibly increasing the episode order and renewal plans for next season. I hear CBS declined to discuss either issue and has chosen not to engage in any communication with the studio regarding the future of the show.
When a new broadcast series is picked up, that typically comes with a six-year license fee deal between the network and the producing studio and matching six-year pacts between the studio and the cast. When the six seasons are over, the network has to negotiate a new license agreement with the studio (usually shorter-term, one to three years). Based on that, the studio negotiates new contracts with the actors. Ideally, that is done early into the sixth season of a show, so the cast can be locked in for Season 7 and creators can plan the storyline. But that happens more and more these days as the networks are holding tightly their purse strings and try to postpone their renewal decisions until the last second.
You can read the full article at Deadline.