It's really the unions that are the problem and that's really a local issue. The school won't hire or promote from outside where necessary, they protect their own, and the teachers are largely protected from termination even if they suck. What you get is whoever was hired, even if it was a shit choice. Teachers should be at will employees and not protected by the financial and political power of the SEIU, which can crush any municipality with lawfare over complex contracts (many teachers unions in California are SEIU).