Just like companies, a school can be notable for being a widely publicized failure. In the one case it may no longer be listed on a stock exchange, in the other, there may be no notable alumni.
Notability should not depend on the size or success or the nature of the community. It's a question of there being something worth writing about. There is no point in merely repeating directory information findable on the web, & if more cannot be said, there should be no article.
Of the NYC public elementary schools, 2 have articles in WP. They are both excellent schools. One of them wrote a few lines about where it is located & which school board it's in. The other has a real article. What we need is good articles, and while we accept anything in some areas, we do not encourage good articles. -DGG