If it is a problem for theists that they restrict which books they will engage with, then isn't it a problem for atheists that we will not engage with scriptures?
I think when we try and understand the religious we need to be more careful to remember that there is no god, and that organized religions are just social phenomena that have a role in our culture. What do they do? What do they say? What impact does that behavior have? I think we will come to different understandings if we stop focusing on the fact that their books contain fairy tales. Talking about the fact that there are no fairies doesn't seem productive.