To reiterate the initial thrust of both pieces, there is little reason to think that having the mayor run the schools will result in an improvement in the quality of education. This is not because the mayor is evil or stupid or anything nefarious; it is simply because he is trying to solve a very difficult central planning problem, while facing pressures from various lobbies. Just as when production of cars or food is centralized, the result of centralizing education tends to be a one-size-fits-all, bureaucratic, poorly-run mess. There simply aren't incentives in place that would encourage or even allow the mayor to find the right ways to run a school system. Competition, on the other hand, should help with this problem. We don't need to find the "right way" to build a car; we let many companies build cars, and let consumers decide which ones are right. Firms compete over consumers' dollars, and in so doing try to find new and better ways to make those consumers happy.
Markets are not perfect, but perfection should not be enemy of the good. We're simply not likely to get persistent improvement in schools so long as schools are in the hands of a government-enforced monopoly. The piece in The Tennessean contains the following: