Why does every conference have their own officials?

[HuskersNow]

I know that the NFL and NCAA are very different, but look at how the NFL uses officials as opposed to the NCAA. In the NFL, officials are held accountable by the league and not just a conference or division. So why in college football do the conferences get their own officials? Why can't there be NCAA-wide officiating crews?

 

I honestly don't know very much about this so I would appreciate it if you could enlighten me.