What is literature? Do we always know in the present what will be judged as literature in the future? Of course not! Quite often what we consider to be literature now is work that has stood the test of time. When Charles Dickens was publishing his greatest stories, they were popular culture, as were the plays of Shakespeare. Much of what is in today's curriculum was at one time popular works. The fact that something is new and popular does not necessarily imply that it is without literary merit or unworthy of study in the academic curriculum.
Now, the question you might want to consider is what popular works should be considered in an academic course of study, whether that be on a K-12 level or in college. Does the work reflect universal themes that we want students to consider? Does the work portray a world that we want the student to learn about? Does the work offer the student a mirror with which he or she can learn something of value about him or herself?
There are works in our popular culture that are such works, and the examples are countless, ranging from Where the Wild Things Are to The Swerve. We cannot know whether or not they will stand the test of time, but we if we do not include popular works, we will be throwing out the baby with the bath water. All we can do is make our best judgements and provide students with good literature that engages them.
I should add, in all fairness, that there are people who do not agree with this position, those who sincerely believe that "popular literary work" is an oxymoron and who would like to preserve the "canon" of literature that was frozen in time many years ago. I do not believe that this canon should be disposed of, but surely, there is room in the curriculum for both.