There is something different about working for the public. And if you aren't working for the public, the school board is.
I agree with your sentiments that "At first it bothered me" and that some people should not have more privacy than others. It would bother me if my salary was publicized, it would help criminals in determining who to rob or identity to steal, and it would put me on unequal footing with people who don't draw a salary and therefore have greater financial privacy. (Such as investors, landlords, pensioners, etc.)