I'm betting (hoping?) this was done with a bit of tongue in cheek, especially since there's a nice, close up picture of the list and it uses up significant board real estate.
Humbling kids with some self awareness is great, especially in middle school. Self reflection and metacognition (why do we do what we do?) are super important tools for kids and leads to more empathy and better conflict resolution.
If this is just a teacher being a crotchety conservative, then yeah, you're right. But I'm willing to bet the kids even helped make the list and had a good time doing it.
Just as in any job, there's the chance of pressure from above and the side. If the squad, squad leaders, or even higher up would make life hell for non participants then they might just participate regardless of their belief.