i'm going to stick my neck out & say something unpopular.
the concept of 'family holidays' is a modern, western one. other societies don't have this idea. we don't need them, however much we like them, and if you can't afford one, you're not suffering in any real sense.
however much we enjoy holidays, we have no 'right' to them. the things that kids learn on holiday can be learnt at weekends/day trips etc, whereas i doubt very much if children receive several hours of academic input each day whilst on holiday. families do not become less of a family just because they don't get a holiday each year.
our own desire for this treat is only part of what makes them so expensive. the harsh fact is that it IS expensive, both in human-made monetry terms, and also in resources. even if the demand were 'spread', the cost of fuel, food, hotels etc would still need to be dropped & would only go so far towards a price cut.
i live in the states, where there is a 3 month summer holiday, and different states/regions do have different holidays, varying by up to a month, but the cost of flights stays high right across the summer.
so, i don't think that any tinkering with the education system (which, i think implies some twisted priorities, re-organising an entire business, just for the sake of holidays) OR lobbying of govt, travel co.s etc will make a blind bit of difference.
having a holiday is like driving a good car, very many of us want to, but if you can't afford it, you just gotta suck it up.
having said all that, a child missing a week of school occasionally is no biggy, but one or two weeks a year is going to make a very real difference to their educational results, career prospects etc. so the one-off week for a special reason seems ok, but not those who take kids out of school once or twice a year.