The opposite is true. In Chickasha, Florida, the government teachers don't care that they have ruined the failed student's GPA, which will have a huge impact on her college applications. The school does allow five absences if some of them are for authorized activities, which means an activity that is approved by the government. The policy is similar to curfews, which allow teenagers to be out past curfew IF they are participating in a government approved activity. One of the main reasons for her school's strict attendance policy is money.
Most government schools receive funding based upon attendance.
If students don't show up for class, the school gets a smaller check from the state and federal government. And since a school can lose thousands of dollars if a student leaves school, slackers and trouble makers are rarely expelled. Unless, of course, they have guns. In the free-market, private schools strive for high test scores and high graduation rates. Attendance is important only if a student is performing poorly.