There are two types of Christians. The first type believes that the stories in the Bible are historically true, and have actually happened. These Christians are very common (especially in the USA, where they are the majority). These are the Christians that I (and most other Atheists) are especially trying to reach, because they often harm others with their believes.
The second type of Christians believe that the stories in the Bible (like Genesis) are not meant to be taken literally, and are simply parables or metaphors. These Christians are quite common, but to a much less degree than the other type of Christians. While these Christians are often not fundamentalists, they are quite annoying in their own way.
The reason these kind of Christians are so annoying is because they usually target Atheists instead of other Christians, even though they often agree more with Atheists than with other Christians. They accuse us of taking the Bible literally, and try to make us look just as ignorant and dishonest as the fundamentalists.
What they don't realize, is that many of us only use the literal interpretation of the Bible, because that's what our opponents do. If you want to argue with someone about a text, you must try to look at this text from the same perspective as your opponent. Otherwise you and the other argue about different points of views, and you'll never come to a conclusion.
Another reason we often take a literal approach to the scripture (meaning that we view much of it as a failed attempt to record history, instead of a way to teach a moral lesson) is because much of the scripture can't be considered to be meant metaphorically. What I mean with this is that these texts are often excessively brutal or repetitive, so even if it was meant to teach a moral lesson, it could have done a way better job. Not only that, but many of these ''metaphors'' are very difficult to interpret, and could teach pretty much any moral lesson without actually being meant to teach that lesson. Because of this, it's more likely that there actually is no lesson.
If you don't get what I mean with this, watch "The Tale of Scrotie McBoogerballs", an episode from the serie South Park. This episode is a brilliant satire on how people misinterpret liturature to make it seem that the stories have a deeper meaning when they actually don't.
Another thing what bothers me about these Christian moderates is that they focus on Atheists, while ignoring that most Christians actually consider the Bible to be a historical fact. I know that many moderate Christians also scrutinize other Christians (and they are welcome for that), but there are also many who don't. Maybe they do this because they don't want to accept how distant they actually are from the religion which they claim to follow.
Moderates, please think about this when you're bothering an Atheist for ''taking the Bible literally''.