My attitude is that having realistic expectations allows you to be positive. Back in the Big Sam days my expectation was that he kept us up, that was it. So his first half season finishing 15th was great, his full season finishing 10th was great, the season up to him getting sacked in 13th was great. As a result I spent the time going to games with my 6 mates, pub crawling through Mill Hill, standing at the back of the Darwen End, starting songs constantly, helping raise money for the massive flags, generally having a cracking time.
At the same time we had half the fanbase who expected a return to the Hughes era, i.e. qualifying for Europe and playing "good football". They spent that period moaning about hootball, chanting "4-4-2", chanting "Benni McCarthy" when he was on the bench.
There's nothing positive about having unrealistic expectations, it just results in anger when those expectations inevitably aren't met, and then finding a scapegoat to blame for it.