Schools are merely implementing national policy. You can thank Michael Gove for that one.
As a disclaimer, I value education. There is no way I'd take my DC out of school on an annual or even semi-frequent basis for a holiday. (My understanding is that parents are not fined for up to a five-day absence, anyway).
But I am the parent. On the very rare occasions I do deem my own family circumstances to be exceptional, then I am the one to make that judgement call; not the Nanny State. As an indicator, DC is now halfway through Year 6 and I've done this precisely once, for one-day only (entailing a 2pm finishing time at that).
Also, I'm well aware of how skewed a great deal of educational so-called 'theory' really is. Whilst there is evidence that regular attendance and results broadly correlate, the assumption that quantity of time spent in classroom equals quality of education is quite simply wrong. There's also a lot in the National Curriculum that simply kills any spontaniety and joy in learning, as could be gained from the less conventional methods sometimes used in teaching before its implementation. The English GCSE and A' Level syllabuses are a case in point. They are woefully out of date and putting kids off reading, because they are being taught in schools in such a dry, uninspiring manner. And the results show up all-too plainly when students arrive at university.
Educational standards are very definitely down. Rigid enforcement of attendance and uniform policy are apparently doing nothing to buck that trend - because this is the easy way of signalling to the public that something is actually being done about it.
It isn't. And incidentally, the fines are a nice little earner for them on top of this.