Miriam Burstein correctly notes that to the literary historian "aesthetic objections are neither here nor there" if a particular text has proven to be influential on subsequent writers. Whether that text might be "overrated" in purely aesthetic--or, for that matter, any other--grounds is irrelevant if an accurate account of genre or period is your concern or if looking at the broad sweep of literary history is of more immediate importance than the aesthetic credibility of a single work.
However, Miriam expresses her concerns about the relevance of "aesthetic objections" in the context of pedagogical practice, of the way in which literature is taught in academic courses: "I still have to teach the book (if it's in my field, anyway)," she writes, "whether or not I want to throw it into the nearest recycling bin." Balancing historical and aesthetic issues is "the great challenge of developing a survey course."
I don't disagree with anything Miriam says here, but what she says does underscore the extent to which the prerogatives of academe, of instruction more broadly, dominate our view of "literary history," perhaps in some cases even shape the way literary history is brought into being in the first place. The purpose for which surely all novelists or poets want their work to be received--to provide aesthetic pleasure, to entertain and provoke--is displaced for the academic critic by the need to chronicle, categorize, and contextualize. Indeed, as Miriam herself concedes, "from the POV of literary history, it's quite possible to 'overrate' a novel's importance (the extent to which it attracted imitators, was genre-changing or -originating, etc.) by pointing to its aesthetic superiority."
As a move made as a reponse to the perceived requirements of a "field," such overrating makes sense. But if the requirements boil down to a novel's capacity to spawn imitators or alter genre conventions, then plenty of aesthetically superior works are going to be excluded from survey courses. Tracking the development of formulas and genre-bending (not breaking) becomes the "subject" of literature courses and scholarship, and, although this approach does not displace actual literature from literary study as directly and thoroughly as does the focus on theory or cultural study, it does still remove the experience of literature--the opportunity to read the most potentially rewarding works of fiction and poetry--from the center of attention. From the perspective of a "literary history" by which such history makes us aware of the most rewarding works it has produced, this makes less sense.
But then the attempt to make literary study a way of invoking this understanding of literary history has already failed, anyway, as William M. Chace's recent article in The American Scholar attests. It probably deserved to fail, since the emphasis on deep reading experience was never really compatible with the accompanying belief held by many older-style literary humanists that, as Chace puts it, "this discipline had certain borders and limitations and that there were essential things to know, to preserve, and to pass on." Either reading great works is a series of singular experiences during which "essential things" are always open to question or it is part of a pre-established curriculum to be preserved and passed on. It is either the opportunity to find and follow one's own reading bliss or it is done within the context of a "field" to be demarcated. Since in each case the latter is much easier to accomplish than the former in an academic setting--to even justify as academic activities--it is unsurprising that determining what are the best books to teach has won out over discovering what are the best books to read.