The primary reasons are that religious schools often offer both superior education and superior safety for the students. This is often true in large cities. In such settings, the graduates of religious schools are more likely to be accepted into accredited universities, and the students of such schools are less likely to become the victims of violence or drug addiction.

It's not uncommon for non-Catholics to attend parochial schools, because their parents may feel that the classes are smaller, they'll get more individual attention, and the discipline will be better. Some non-religious people may think that about other types of religious schools.

I've seen a lot of non-religious students end up in religious schools as punishment - or as a way to either keep them out of trouble or to learn how to do right.

I have no personal experience, but I would imagine non-religious students may be sent to religious schools by their religious parents.

I don't have personal experience, but one reason might be because so many public schools are horrible. If the parents can afford it, it's worth the extra expense to send their children to a private school where they can get a better education.

What Joshua said. How often have you heard of a student picking out their school? Before, say, college level.

Parents invariably choose the schools their children attend.

Parents.

I can't believe that there are still religious schools still operating,anyway they should be banned for child abuse filling childrens heads.with fantasy and making them live in a delusional lifestyle withought giving them a choice how disgracefull ok.

Religion has analogs in secular culture. Normal subjects are taught with references to values and insights to the spiritual alongside facts and dates and the scientific method.

Such wholistic education is superior to the convention of separation of human values from history and technology.

Exposure to thoughts that are distinct from popular culture makes for more thoughtful living.