Unsaid in this piece is that school administrators tend to leave as the stench of corruption around them gets just a bit too powerful. The details haven't always come out, but in my time in Philadelphia "stealing all of the money" seems to have been the top priority of the people in charge, and the people who put them in charge don't seem to mind all that much.
But, yes, if the schools suck it mostly isn't the fault of teachers. The bosses are the bosses, and they're generally corrupt and awful.
