From what Bird’s said in the past, the issue wasn’t that IU was too big as much as just too “different” …especially economically.
He was a dirt poor kid from a rural broken home who apparently showed up at IU with only a couple pair of jeans and T-shirts. And then suddenly found himself surrounded by rich kids from the Indy and Chicago areas with designer everything. That new world made him so uncomfortable that he just wanted return home to the world he understood.
It’s actually quite similar to the reason kids from deep Eastern Kentucky often turn tail and run home after tasting the bigger world. UK might’ve been a better environment than IU in that respect (perhaps our boosters might’ve helped him out with the economic woes), but alas, we’ll never know.