Of course Whenim- as an experienced teacher, head of faculty, senior teacher and governor- sadly the majority of kids taken out of school for hols are not from 'responsible' parental background, and do not go on 'culturally and educationally enriching' holidays. And mane have special needs and are already way behind and struggling.
In the past, schools took each case on its merits. Very time consuming for those involved, with appeals, etc. End result being something like 'if your kid is bright and you go for a 'middle-class' holiday and sit your kids down to school work a couple of hours a day (and yes, it takes staff hours to prepare, mark on return and help kid catch up), then it's OK. If your kid has problems and you are going to Benidorm to eat fish and chips and drink beer, it is not. Imho, it is best to state clearly that holidays in school term is just not allowed, unless there is a really powerful family situation or emergency. Saves Heads and Governors hours and days or arguing- teachers from having to work hard to help set work, and help kids catch up- planning special work, etc, etc- but most importantly, it is best for the children, especially those with difficulties. As said, in continental europe, this has always been the case- parents really value and respect education- and taking kids out of school holidays would not even enter their mind.
I cannot tell you the number of times parents asked me to set some special work for the kids to take on hols- which took me hours to prepare- only to be told on return they were far too busy to even look at it. Then had to help in my breaks and lunchtime for them to catch up.
And cannot tell you how many times I've visited children at home to set them work and help them, during long-term illness, injury or even, pregnancy.