We know a family here in China with several kids. One of their kids is in ninth grade. At her school, ninth grade is in high school, but her school runs the IB curriculum, where ninth grade is in the Middle Years Program. So basically her school content is middle school content.
Anyway, this family has a relative getting married in America. The mom talked to the kids' teachers about missing some time during final exams. The younger kids' teachers were okay with it, but the ninth-grader's teachers said absolutely not. So the family has to make a trip to the other side of the world fit into a single weekend.
Here's a friendly reminder for all you middle-school teachers out there: you're reciting scripted content, not curing cancer. The same goes for high-school teachers, and college professors, too. Life is more important than stupid exams that don't mean anything. "Oh, they mean something, all right! Your scores in middle school affect which high school accepts you, and that affects which college accepts you, and that affects the entire rest of your life!" And the shirt you didn't wear today is why you'll die alone. Instead of chaos-theory-ing middle-schoolers into neuroses, tell kids that: 1) no one's life is completely optimized, and 2) that's okay. You don't need to go to THE best college, and you definitely don't need to be there for EVERY middle-school exam.
This is related to my dust-up with my sociopath colleague a few months ago. When you understand declining marginal utility, you know that the optimal amount of anything is never "as much as possible." My colleague thought this meant I'm not passionate about education. Instead, what it means is that I have no cognitive dissonance between my ideals and my behavior. If there comes a time to call it quits on some activity (and despite the words you say, I guarantee you call it quits at some point on all activities in your life), then you've already conceded that a sub-maximum is optimal. Spare us your moralizing; it's out of place here. This isn't a battle of "right" and "wrong," it's a difference of opinions.
On a somewhat-related note, when we started homeschooling, it was really something I very much supported and my wife wasn't that much against. However, at least once a month or so, my wife spontaneously expresses gratitude that we homeschool and don't have to deal with insane social justice warriors or pocket tyrants controlling our lives through our children. If I were in my friends' position, I would not have asked the teachers for permission to miss a middle school exam, I would have informed them of what would be happening, and when they objected, I would have said, "That's hilarious that you think I care." But then, I guess I'm just lacking in passion, right?