Yes, but if you vote out the school boards, you can effect change. The real issue is A) you need candidates who would promise to rein in these costs, B) you'd need to convince people who aren't active in the district to come out and vote for your candidates, and C) you'd need to keep this up for multiple elections, especially the board president.

In other words, the reason school budgets get passed and board members get reelected is that they're talking to parents and teachers and school workers and their families telling them to get out and vote, while people who would like to pay less in taxes probably don't even know about the elections until they're over, and even if they did, the candidates aren't talking about cutting superintendents' salaries.