Seriously-- AS is NOT scientology. School districts that use it do not evangelize scientology. It's a pedagogical method, mostly adapted from self-study approaches. If scientology courses lectured instead of using the AS self study approach, would you want to ban lecturing from schools? Getting upset about AS is just about that misdirected. AS does not teach scientology.
On the other hand, christian and church affiliated schools DO teach christianity. They often have obligatory religion and bible studies classes for promoting myths and made up shit as truth. They discourage critical thinking and inquiry. They spread superstition and promote embedding it into cultural consciousness.
I'm not defending scientology, because AS is NOT scientology. It's a study method. I think it has some merit, although I think it emphasizes self study to the detriment of active group pedegogies a bit more than I think is best practice. I don't have anything good to say about scientology, although in fairness, I don't know much more about it than that it has done far less harm to humanity than christianity has done. That doesn't make scientology good-- it makes christianity something that's even worse in schools.