Year-round school messes with schedules for associations/groups such as the boy scouts too much. Their schedule has heavily relied on 1 long summer vacation a very long time.
Also, it is more difficult to arrange things such as family reunions and things that require similar breaktimes. It can detrimental to family time as it takes more time out of children’s lives. It even disrupts vacations that last 1 month or longer.
2.Budget
Year-round school isn’t very good at being cheap. In the summer months, the electricity bills are up 4-8% for homes, but a school is way bigger so that multiplies it more. non-year-round school would not need to regulate temperature during summer since nobody's there, but year-round schools do need to regulate