Jeff Fisher was a longtime coach. He did make a Super Bowl, but mostly his teams were mediocre. 7-9 refers to 7 wins and 9 losses, which was his record for many years. 7-9 is good enough to get another year, unlike the teams that bottom out and win 2 or 3 games, but not good enough to make the playoffs or win anything.
Varsity Blues is an overwrought teen drama of the 90s with a bunch of people in their 20s playing teenagers.....and it's a damn good movie ngl. But yeah high school football in Texas is indeed pretty insane. In Delaware when I was playing, we had a playoff game in a downstate town, and downstate Delaware is basically the deep south, farmland and small towns and etc. We drove into the town and the whole town was out tailgating on their lawns and when we got off the bus some old dude said "you boys gonna get whipped tonight" (we won like 40-6 or some shit lol)....if that's what it's like in the rural areas here, I can only imagine what its like in those regional high school towns in Texas.