I certainly don't believe that all administrators are good and misunderstood. I don't think I'd even argue that a majority are. However, the paralyzing levels of conflicting interests that need to be managed by a school principal are largely unseen by the teaching staff. A good administrator, on the other hand, can directly empathize with the struggles faced by her educators. Not all admins will act on this empathy or stay tuned into it, but the good ones do.

Not to nitpick, but the only job that allows for greater growth of personnel management skill than teaching is the army. Having 10 years in the classroom is a great qualification for a manager in any field. If an admin is bad at personnel management, he was a bad teacher before he got the bump.

Lastly, I believe you seriously undervalue the importance of having an admin that has worked in the field, and greatly overvalue this "business acumen" that her peers may have acquired in the private sector. I'm in IT, where complaints about management are the same as they are in education. The self selection and fallibility of the promotion cycle is the same anywhere. The key difference, however, is that in IT, the worker bees will rarely if ever get out of the pits. Managers are usually people with passing experience with programming at best. Analysts and client liasons, requirements gatherers, these are the fast trackers, not the hot-shot irreplacable programmers. The good managers are those few who can overcome their lack of understanding AND balance the competing squeezeplay that comes from directors above and their direct reports. They still have to deal with the anger directed at them from workers who unfairly misjudge the power they have and motivations behind their actions. Bad managers make it easy to take umbrage at all decisions handed down from above.

My entire point is that it's going to be more difficult for an educator to judge the quality of an admin than the reverse, having never walked in his shoes. There are some bad decisions that will be made, and certainly some "fads" that will crop up. If you need someone to blame for those, sometimes you can look higher up the chain to the regional BoE. Again, I'm not saying that all or even most admins are good, but make damn sure you know how to tell the difference.