Yes, of course big government types want year-around school. But right now the advantage of being in the teaching racket is you get lots of time off in the summer (not as much as the children due to teacher in-service training but still 5-7 weeks in most systems). What other job offers at least two weeks off at Christmas and a bunch of weeks in the summer and still has a good year-around benefits package? The teachers will cry foul if summers get shorter.
It’s already happened. My son finished school on June 16, and started back again on August 15. Less than two months! Not a real summer at all.