My first school was staffed with ineffective administrators and unmotivated teachers. As a first year teacher, I was on fire and lively. The negativity around me was sucking the life out of me. When the general mood of the adults at a school is negative, the kids pick up on it.
I didn't know any better, so I just kept a lively classroom. The students (near the end of the year) commented about my room having a "different feel" than any other that they'd had at that school. I often heard kids say, "I hate this school". It was depressing. Fortunately, I was naive and didn't know that anything else existed. I decided to look at other schools for a higher salary.
Then I found my current school, filled nearly to the brim with high-energy people (just like me!). The administration isn't perfect, but they aren't nearly as bad as my old school. There are a few rotten apples wandering about, but they are easy to avoid. I'm also thrilled that they don't allow ineffective teachers to remain teaching (even if it means they'll have a difficult time filling the position).
I can't say whether that attitude toward admin is prevalent in public schools, but I can say that life is MUCH nicer when you work with professionals who are similar to yourself with a true desire to improve some kids' lives.