I started following ISU in the mid-1980's, and started attending games in the later 1980's as a student. Hilton Magic "died" for a spell during the Orr era. There were articles about it in the Daily. In an attempt to revive it, yellow "Hilton Magic" flyers were put on all the seats in Hilton before a big game (KU maybe). I think it worked that night, as ISU won.
I think the biggest "problem" this year was with too many of ISU's fans buying into the "most talented team in the Big 12" mantra, which drove expectations to unrealistic levels. As others have pointed out and thoughtfully discussed, it just simply wasn't true. When FF tweeted out that ISU's best NBA prospect was TH and that he was still a couple of years away, many fans chastised FF, a knowledgeable and experienced college basketball commentator.
A couple of memories I have...
ISU was playing Indiana during Christmas break somewhere around 1990, and our break tickets were right behind Indiana's bench. Indiana's big red-head center gave up an offensive rebound/putback to ISU, and Knight pulled the kid out and started reaming him. Someone from the crowd yelled out, "Hey, Bobby, rebound it yourself!". Knight turned around and said to the crowd, "I'm too damn old!".
The rec center had just opened up, and a couple of friends and I went over to shoot some hoops. A few MBB players were there, along with a few MBB wanna-bees. A couple of guys left, so we were asked to join in. I was about 6'-2" 200 lbs. There was a real hot head MBB-wanna be playing, probably around 6'-8", 240-ish, built like a rock. I had to guard him. I didn't let him push me around, and he was starting to get mad. Finally, he posted me up, and leveled me with an elbow/forearm to the head, and then got in my face for a few seconds as I was laying flat on my back. Paul Doerrfeld (ISU player who I think had just graduated), who has on my team (he was pretty big too), picked me up off the floor and got me back on my feet, and said, "Good job...that guy is an *******".