As a former Director of Religious Education, I can tell you that most parents do not think of their child's religious education as really "education." I worked for the Catholic Church where most people think of Confirmation as graduation for religious education. The Church is working on this, but it is still a common belief. Most Catholic schools teach religion every day as part of the curriculum. I worked at a parish that did not have a school, so we had religious ed for 1 hour, 24 Sundays each year. Not exactly the same as 180 hours every year like the schools. We had religious ed for kids in grades K through 11, and boy did parents complain that that wasn't fair. We did not have Confirmation until 11th grade, and some really complained.
I think it's sad that some people don't consider their religious education to be as important as their traditional education.
Please keep working hard for those kids. Not everyone is going to take it as seriously as you do, and not everyone is going to appreciate the tremendous gift you are giving them. I guess this is just one of those areas that you have to be ok with just knowing in your heart that you are doing something important.