Local Politics and Administration.
I mean look at the DISD. 5 Superintendents in 4 years, the last two getting $250,000+ a year. On top of that the DISD has $11million worth of stuff missing/stolen/unaccounted for. Including 11 portalable buildings, a bull dozer, several $100,000+ instruments. In short, they do not know what they have and what they don't have, so they waste tons of money because of it.
Another school district which will remain nameless, spent money adding onto the high school, for the cost of the add on they could have built a whole new school, larger than the one they ended up with. Then the press box was set on fire. What do they decided to do? The insurance money isn't enough for their plans, they build an expensive high tech press box, with an elevator. LOL. The district is POOR, because the district, makes its self poor because of the school board doing favors for friends.
Lastly, coachs(atleast in Texas) get paid $20,000-30,000 more than teachers. Coaches are typically the worst teachers(there are exceptions), you should be paid based on how well you teach. And if you aren't up to par you should be fired(with the Teacher Unions, its impossible to get bad teachers out of schools).