It's also important to note that a low reading grade level for writing is not "bad writing." Most novels fall somewhere between 5th and 7th grade reading levels. Stephen King is typically around 6th grade, and Jane Austin was often at about 5th grade, for examples. There are plenty of writers who convey complex stories and themes at even lower grade levels, and it's not unheard of to read a complex story at even a 4th or 3rd grade level. In many contexts a low grade level does not mean the content is simple or dumbed down--it's just a measurement of the conveyance or style of the writing.