I honestly believe much of the dislike comes from the basis of fandom - fanaticism. A lot of people probably think 'they don't talk about MY team enough,' 'they only cover THOSE teams,' or 'they only ridicule MY team.' Objectively, it's a good TV broadcast. It has a diverse range of hosts, entertainment, good story telling, production value... you name it.
I hate to admit this, but, if I knew Nebraska was going to be talked about more on Gameday then I would probably tune in. If I knew we had a player or program that was going to be part of the debate every week, I would probably tune in. Nebraska's lack of national presence for much of the last 6-7 years caused me to lose interest in the national scope of things. Mostly recently, I think 2009-2010 was the last time I made an effort to go watch Gameday.