The reason the rules changed was essentially because the government didn't trust the schools to register unauthorised absence as unauthorised. It sadly did happen where schools were worried or scared about a parent's reaction so authorised leave when they shouldn't. This makes prosecuting persistent absence difficult.
However, instead of supporting schools and protecting them from thuggish or just belligerent parents, they decided to revoke the school's ability to authorise absence outside of the most exceptional circumstances.
Obviously it's common sense that children who don't attend much school aren't going to do as well as those who do attend. However, the data mentioned in the report said that children who attended for less than 50% of the time did less well than children who had attendance over 95%. Well duh. Less than 50% attendance is not a 2 week break in Corfu. Funnily enough that remaining 5% is just under 2 weeks but the powers decided that combined with the average number of sick days, it was not acceptable. I think what many schools were doing eg only allowing holidays if a certain attendance level was maintained.
"In the past schools were criticised for having high levels of unauthorised absence where children missed school with no explanation. The unintended consequence was that schools got better at authorising absence. Parents who did not send their child to school received phone calls to chase up their child. If the parent gave a plausible reason, usually that the child was ill, then the school would authorise the absence and both the parent and the school would escape censure, but the child still wasn’t there. This focus on unauthorised absence deflects attention away from the most important issue-that all absence is bad for children’s education"
This bit of the report amused me because I think most parents would expect to be believed if they told the school that their child was ill. Even if a school marks a child as ill an ewo will still flag it up if attendance is too low. Unless they are suggesting that being I'll is not a reason to stay off school.
In my personal experience, over a decade in education, it isn't the family trips that cause educational damage. It's the 10 or 20 minutes late every morning or the Friday off because mum was too tired to get up or the general I can't be bothered to take my children to school on a regular basis that causes the long term problems.