It sucks. But its FS1, how many casual fans are checking FS1 for content.
There was a LOT of competition for that same timeslot on better networks.
FSU v Clemson ABC 6.71M
OU v Cincinnati FOX 2.17M
Rutgers v Michigan BTN 1.94M
Virginia Tech v Marshall ESPN2 319k
WKU v Troy ESPNU - 29k
I would not expect SMU to beat the first two, as they are major networks and good teams. Michigan is just...Michigan.
OU v Tulsa wk3 on ESPN2 had 641k - were those numbers primarily for Tulsa or OU
Tulane (last year's Cinderella) v USM wk3 Sat 4 pm ESPNU 53k
La Tech v SMU wk1 ESPNU Sat 12 72k
Just keep winning and the numbers and recognition will increase - see Tulane last year. And its network, opponents, competition, and time - all those come into play for ratings.
https://www.sportsmediawatch.com/college-football-tv-ratings/