OP, I would be furious if I were you.
Obviously, it isn't ideal to take kids out of school, but it's incredibly narrow-minded to say that it should never happen, under any circumstances. I am extremely supportive of the school in general, and absolutely believe in the importance of attending regularly, but last year, we did make the difficult decision to take dd out for 7 days, tagged on to half term. DH is from a very remote village in another country, and his elderly mother was seriously ill. It takes three days to travel to his village, and another three days back. Given the overall cost of the trip and our belief that it could be the last time for dd to see her grandmother, we felt justified in taking her out of school, and thankfully the headteacher agreed, and authorised the absence.
I am quite convinced that dd learned more in that visit than she would have learnt in school. We used some of our time overseas to focus on the topic that her classmates were studying at home, looking at it in the context of the culture that we were in. She wrote up a little project on the topic which she presented to the class on her return, enhancing her own learning and theirs. She also practised language skills, learnt about farming techniques by joining in with what the local people were doing, and absorbed loads about a different culture and way of life which is very much part of her heritage. And she spent precious time with her grandmother and her other relatives.
Holidays in term time are not always about avoiding the crowds or saving a few quid. There are very real reasons why we simply cannot travel to my DH's birthplace during the longer holiday periods, not least because it wouldn't be safe to do so.
I am simply not willing to sacrifice my daughter's relationship with her grandmother for the sake of a few extra days in school, and I would be furious if the school sought to punish my dd for decisions that my husband and I have made about what is right for our family.
Thankfully, our school seems a lot more enlightened than the OP's.