No offense but that's a misguided statement. Baylor is consistently in the Top 10 in the nation in WBB attendance.
Keep in mind, Baylor has half the enrollment of ISU (15,000 vs 31,000) and half the living alumni (120,000 vs 220,000). Waco is a city of about 125,000 people while ISU is 30 minutes from Des Moines with half a million people. The two largest concentrations of Baylor alumni are in Dallas and Houston, the former 1.5-2 hours away and the latter at 3+ hours away. That would be similar to ISU's biggest alumni bases being in Omaha and Minneapolis. For midweek contests, that distance is a huge hinderance for most. Lastly, both Houston and Dallas have MLB, NBA, and NFL franchises so, whereas football fans in Des Moines will make the short drive to Ames for all the games, Baylor fans in Houston (as an example) may split loyalties with Baylor and the Texans or the Rockets, etc.
It's just a very different set of circumstances.