Iowa plays the opposing team's fight song leading up to every away game. This is not to say that there wasn't a huge emphasis put on the CyHawk game last year. Ferentz was legitimately on the hot seat at that point, another loss to Iowa State could have been catastrophic for him.
Over half of the fan base was furious going into the '15 season and most did not expect anything more than seven wins. Iowa's home opener against Illinois State barely drew 60,000 fans, the emptiest I've seen Kinnick in 16 years.
I said before last year, that the Iowa State game was the most important game of the Ferentz era. I really felt it would be his last season if he lost that game. The anger of the fan base would have reached a boiling point that Ferentz would not have survived, unless the team won the West, but I'm not so sure if that would have happened after a bad early season loss like that.
I think more than the mediocrity from 2011-2015, fans were sick of losing to Indiana, Northwestern and Iowa State every other year. Shockingly, Iowa has a better winning percentage against Michigan, Penn State and Wisconsin in the Ferentz era.