IF we had kids, I would swear that Anna was my husband!

My husband feels the exact same way as Anna does, but we don't have kids and this isn't going to come up as a decision we will need to make.
He didn't get to attend his own graduation ceremony from high school, due to an ill-advised and ill-timed disagreement with the principal. The thought that treating smaller milestones as as important as high school or university graduation when they haven't finished their formal education is what sticks in his craw. Everyone gets to graduate *something* at some point is where the idea that this is akin to 'everyone gets a medal.' He suffered the consequences of his actions, but now no one else has to. At least I think that's why it bugs him so much.
My own high school didn't call graduation *graduation*-- it was callled the school leaving ceremony, or commencement. We couldn't call it
graduation because our final marks weren't released by the provincial government until August and school ended in June. We had caps and gowns and a presentation of little rolled up pieces of paper that said we finished the school year. Not completed successfully-- simply managed to make to June without quitting or getting kicked out. I was valedictorian and my speech was all about how significant that night was as a rite of passage. Still... a small part of me thought it was a farce because everyone got to attend, regardless of whether they passed their classes or not. And regardless of whether they were actually leaving the school or not. A number of my classmates had to go back in September to complete their course work to actually get a diploma, so at my school, everyone indeed got a medal. That being said, if my parents weren't going to let me attend because that ceremony didn't actually result in my being handed a diploma, well there would have been a hissy fit that only an 18 year old girl could throw. And I would have attended anyway, because well... I was 18.
My university graduation ceremony-- that I took seriously. That was a Big Deal. And I was strictly top-of-the-bell-curve average kind of student. Attending a farcical
aquatic ceremony four years previous didn't make me any less of a hard working, goal oriented student.
I see where Anna (and my husband) are coming from and I like her strategy of misdirection with her kid, but I don't actually see soul-crushing harm from participating (or even not participating) at that age level.
No etiquette violation for taking a moral stand on something, just so long as her morality doesn't harm or injure anyone else. This choice reminds me of the kids who didn't get to participate in the Christmas pageant, or got the day off of school to avoid Halloween parties because of the parents' belief systems.