This happened to us about 5 years ago. Through our attorney, we threatened to sue our school if they bothered us again about this matter. They stopped.
We have taken our boys out of school for vacation every year of their lives. My oldest is now 20 and in college. My youngest is now a Junior in HS. They both get awesome grades, take AP classes, score very well on the SATs, etc.
They are my kids, not the state's. I decide how to best educate them, and having a well-rounded life is a part of that education. What a student learns outside of the classroom is so much more important than what is learned in the classroom. Most teachers get it. It seems to only be school administrators who don't get it, and it is probably about $$$, not the kids.