Sophomore year of highschool my school had a new attendance policy where if you miss more than 4 days of class you automatically failed the class unless you did after school detention for each day of class pass 4 that you missed. What made the rule stupid was that there were no excuses allowed, so that if you were sick for 5 or 6 days you'd either fail or have to do a bunch of after school detention. The school changed it the next year to allow for excused absences, which is what it should've been to begin with.
This is the kind of shit that made me lose all faith in school administrators. Extreme mandatory attendance rules have absolutely nothing to do with curriculum, and everything to do with money. They - almost without fail - disproportionately impact disadvantaged students. I'm lucky that I finished on-campus college before they implemented mandatory attendance at college too, or I would have outright failed. There were so many times that I'd have to miss class because I got stuck at work. I would cram extra hard for tests when that happened and still pass with good grades. But under the new rules I would have failed all of my classes.