Thank you for writing and we appreciate your feedback regarding this matter, I would like to point out that in the family tree builder software you can write your own custom fact - for example you can write "Religion: Quaker" by double-clicking on the person > Going to the Facts Tab > Choosing New Fact > And instead of choosing from the list - type it down.
However, we won't disregard this feedback and we will take it into account as there are indeed religions that we have missed.