I teach high school and never miss a game... but you're right, a lot of people don't show up. Even parents at times. We're a relatively small town (50,000) but only one high school in town with about 2300 kids. Many of the folks who live here didn't go to school here, but when I talk someone into coming with my husband and me, they always have fun. We even go to all the away games (the nearest away game is 75 miles, the farthest more like 200 miles).
I've been in this district 20 years and we're having our first winning season that I can remember... we're 6-2 with two more games to go.... have my fingers crossed. If we win those two we should be in the playoffs.
Tell your son to have fun teaching.. it's the best and hardest job in the world!