Do you think they take it literally because people want stuff laid out 100% for them so that interpretation is not needed? Taking the Bible literally would practially eliminate the need for interpretation.
Taking the Bible literally would not allow our minds and hearts to grow to the extent that it does when we use the Bible as a resource to our Christian faith.
Kind of like how when reading a novel, we try to look for the meaning, not only in the words written, but also in what the author was trying to say. If we take things on surface level only, we miss a lot.