Not just sports alternatives, but just the sheer amount of activities available to you in the Twin Cities vs mostly just eating and drinking in Ames. You start to get desperate for something fun to do, and having a major college football program in town would be a good option.More or less this. Imagine the Nebraska fan base but without the historic success, and you'd get something pretty similar to ISU. I've talked about this a lot recently but the existence of other sports alternatives makes the standard for a strong fan base much higher. Someone recently compared the Gophers' basketball attendance to other metro area schools and it's actually on the higher end. I'm sure football would show a pretty similar trend.
I'm speaking from experience as someone who moved from the Twin Cities to a town that's nearly twice as large as Ames, and I'm still bored to **** here.