Utah brings a TV market that is already had by BYU... they bring a fan base that would be similar to TCU and Houston in a much much much smaller market than TCU. They added absolutely ZERO value to the PAC12, regardless of what they did on the field. They have absolutely ZERO national appeal whatsoever.
Academics wise, sure they are an AAU, but would be like 5th or 6th best academic program in the conference, Add Washington and Oregon and they suddenly drop further. They have the small endowment of all the BIG12 schools. There is nothing to gain from Utah being added unless the sake to expand is just to expand.