That's an interesting thought -- what should and should not be an excused absence.
I completely agree that teacher's aren't able to use common sense anymore -- I'm not saying they don't have it -- just that they don't have any flexibility. There was an interesting discussion on an education forum that I visit the other day, it was about using rubrics to grade, and students taking risks on assignments.
Teachers mostly hated the rubric and thought that simply meeting the conditions of the rubric should result in a C grade. They wanted their students to take more risks and be more creative in their approach to assignments.
(Some) students thought that meeting the conditions of the rubric should always result in an A grade. They didn't understand why "style" should matter, thinking a bone dry, basically unreadable paper that met the conditions of the rubric were all that counted.
And don't even get me started on zero tolerance policies. Teachers seem to hate them as much as the students and parents do. (One of the things that most amazed Mo about his new school is that they had knives in the cafeteria.)