Why a Summer Vacation?

So (for obvious reasons) I have been thinking a lot about education lately (well it is always there in the back of my mind) and today I had this thought as I was folding laundry.  If teachers were offered a higher salary I think many of them would be more then willing to work through the summer and not have the two months (not three, Mark only has June and July off he starts school the first Monday of August)off. Most often when people talk about teacher's salaries they say that they don't deserve to earn more because they have summers off. (Who cares that they have 4 year (or more) degree like everyone else, stay late, spend a fair amount of their own time (and money) planning, and oh yeah work with kids of varying abilities/attitudes all day and parents of varying abilities/attitudes?)  My question is why do schools still have summers off? I do actually know why they originally set such a school schedule (and this article explains it simply, its really short, although it its from 2007 but I still think the ideas are valid) but I personally believe the long summer vacation is outdated.  Students do not need a long summer vacation and I know that Mark as a teacher would be okay teaching though the summer especially if it would end the argument that teachers don't deserve as much money because of the state set not school set teaching schedule. The state not the school district decides how many days are in a school year.  Mark currently has  2 week breaks in October, December, and late March. If they added a break in the summer then that would provide plenty of opportunities for families to have a vacation together (all the vacations could just be a week long) and kids some time to be a kid.  I think students would learn more because they would not have to be retaught so many things.  So many studies show that students score lower on tests in September then March because they have been out of school for 2 or more months, not learning as they are in the school year.  In the article I linked it talks about how other developed countries have much longer school year.  Like 216 and 240 day school years where as the US has like 180 days in a year.
People always talk about how great it must be to have summers off because you can go and do all kinds of things and travel all over.  In reality its actually kind of boring because you don't have any money to go and do all the fun things and if you live in a hot state you don't have enough money to run your AC.  We come up with some fun things to do together and I love being with Mark but it is certainly not some glamorous vacation.  Also kids get bored too!  They need structure and routines.  They may not love being in school but they are with their friends and not bored at home all day too.  It would also help parents more too. 
One big reason why we don't have longer school years?  Because schools are expensive to run and if they have to be used more in the year it would cost more and putting any more money into education is clearly not an option with our Government.  So people will continue to argue that teachers should not get paid more because of a summer vacation they did not ask for (of course they enjoy their summer but they did not ask for it) and students do not really need. But how does one go about changing the amount of school days in a year? This I do not know.  The United States is falling farther and farther behind other countries (especially in math and science) and our Education system is a contributor to that.
Mark just wishes he could teach history and help students.
These are my thoughts today.