CU didn't defect.  Texas with a little bit of help from Oklahoma forced the move.  Nebraska left too, if you didn't notice.
Sports bring money to schools.  UNC has dedicated a lot of their efforts to get to a FBS conference in all their major sports, so they have dedicated themselves to the "Jock World".  They had dominated the FCS and wanted a little more.  I hope they win the Big Sky conference.
Out of conference scheduling is always a problem and with CU having a contract to play one of their games in Denver, they needed to get another home game to support their local sponsors (restaurants, hotels, etc) in the Boulder area.  
They have non-conference games against Nebraska coming soon. I hope you will be happier and more informed by then.