I understand your point. However, there are many others with similar stories. It is very difficult situation. I am not objective because of my personal experience. But I strongly believe that all children deserve religious education even if their parents don't. Children are far too precious to give up on so easily.
I'm very sympathetic to your point of view, and would do anything (and have done much) as a teacher to get them to worship the Lord every Sunday. But this is ultimately a matter of their free will and grace, not my pedagogy.