Edit: It was mostly because it was played at SMU’s smaller stadium
Probably a few reasons for that.
1. 54-10 season and first of INDY so less fan interest overall
2. BYU had recently played TCU in Jerry World (and lost)
3. Tulsa probably didn't bring many fans
Still, was kinda surprised to see that, given the narrative that we have a large fanbase in Texas.
WikipediaThe Armed Forces Bowl, formerly the Fort Worth Bowl from 2003 to 2005, is an annual postseason college football bowl game. First played in 2003, the game is normally held at the 45,000-seat Amon G. Carter Stadium on the campus of Texas Christian University in Fort Worth, Texas. The 2010 and 2011...
https://en.wikipedia.org/wiki/Armed_Forces_Bowl