Jugglingfromheretothere - do you mind if I ask how old your children are? Because I can see a certain justification to the belief that a fortnight's holiday during termtime, when a child is in primary school, doesn't cause any problems educationally for the child, I don't think this is true when you get to secondary school - particularly when you get to years 10 onwards.
In those years, the children are learning the curriculum upon which they will be tested in their GCSEs, AS levels and A levels - and a child who is away for a week or a fortnight might, as a teacher upthread said, miss the only lesson in which a particular element of the subject is taught.
I know that they can copy up notes, and catch up that way, but they will still have missed all the discussion in the classroom, that is just as much a part of the teaching as the notes are. After all, if just copying up the notes was as good a way to learn these subjects, why do we bother with teachers at all? Why not just sit kids in classrooms, with someone to make them keep quiet and work, and just give them notes to copy up?