3/10. I'm happy that BJ wants to continue fighting, and I understand that he has done enough in the sport (and for UFC) to be able to pick his opponents, at this late stage in his career. It's understandable that he wants to avenge a loss, especially with how close the first fight was. It's also good that he's not being used as a stepping-stone for a younger prospect (as was the case with Rory).
All of this being said, the BJ-Edgar rematch showed that BJ could not catch Edgar, and will likely be outpaced/outstruck for yet another decision loss. For his part, Frankie needs to get to having better than a 1-3 record, and perhaps the face time on TUF will help get the casual fans excited about the next (undeserved) title shot he is gifted. The TUF taping also keeps him out of the FW/LW title picture long enough for the Pettis-Aldo situation to get sorted out.
TL;DR version: there are many reasons why this fight makes sense. None of them make it a compelling one to watch.