Battered fan syndrome. I think a lot of people just aren't comfortable predicting a win unless we clearly outclass the other team in talent. That's why you see a lot of 7-5 predictions where our only wins come against the 4 cupcakes (BGSU, Western Carolina, Vandy, NT), Kentucky, South Carolina (because we've won 2 in a row), and one more SEC game along the way.
Based on results from the past 5 years, it's hard to believe that our coaches and this team can roll up on another equally/more talented SEC team and pull out a win without us having a significant advantage heading into the game. That's just the perception right now. Losses to UF and Vandy in 2013 and UF in 2014 don't really help matters, either (although the South Carolina win in 2013 gives me some optimism).
I think we'll go 8-4, possibly 9-3, but....it's the Vols. It's hard to not take a "I'll believe it when I see it" approach.