According to the Las Cruces Sun-News, New Mexico State joined Alabama on the list of teams that have turned down a CBI bid. 

The NMSU athletic director told the paper that it wouldn't make financial sense for the school to host a game because it would cost the school $60,000 to host the even and he was unsure if ticket revenues would be able to pay for it. 

Other than having teams like New Mexico State turn down bids, I'm not sure what's taking the CBI committee so long to pick the field of 16, but I'll pass along the information regarding Rider as soon as I get it.