Nellcote, you are absolutely right. All unions exist for the benefit of their members, not the “customers” of the entities that employ the members. This is not a secret, and there’s nothing wrong with it.
What I object to, however, is the NJEA and other teachers’ unions trying to get political points, and hence goodies from politicians, by claiming that what they do is “for the children”. It’s NOT for the children, it’s for the union members.