Of course, there are good reasons for rushing a bit with an English dissertation. One of the biggest is exactly what is stated in this New York Times piece (which I presume many readers have already seen):
Fighting these trends, and stretching out the process, is the increased competition for jobs and research grants; in fields like English where faculty vacancies are scarce, students realize they must come up with original, significant topics. Nevertheless, education researchers like Barbara E. Lovitts, who has written a new book urging professors to clarify what they expect in dissertations; for example, to point out that professors “view the dissertation as a training exercise” and that students should stop trying for “a degree of perfection that’s unnecessary and unobtainable.” (link)
Of course, the pressure to come up with something original is not trivial. And elsewhere in the same article, it's pointed out that most Ph.D. programs in the humanities (including Lehigh's) require significant teaching commitments from their graduate students. It's hard to write a 200+ page dissertation while also teaching one, or even two classes a semester. Many students, especially those with young children or mortgages to pay, often find they also have to get teaching gigs during the summers to make ends meet. With such commitments, three years on a dissertation can easily become six, eight, or even ten.
Some students take forever to write because they're caught up in the quest for perfection. But far more end up as "tenured grad students" because these other commitments can make a serious focus on research quite difficult.
One of the increasingly popular methods for staying on track in English is the writing group:
Those who insist on dissertations are aware that they must reduce the loneliness that defeats so many scholars. Gregory Nicholson, completing his sixth and final year at Michigan State, was able to finish a 270-page dissertation on spatial environments in novels like Kerouac’s “On the Road” with relative efficiency because of a writing group where he thrashed out his work with other thesis writers.
“It’s easy, especially in our field, to feel isolated, and that tends to slow people down,” he said. “There’s no sense of belonging to an academic community.” (link)
I did not have this; it would have been helpful (indeed, it still might be helpful for me even now), though I do wonder about whether I could have found other dissertating students with whom I could have had productive conversations about work that was often only starting to be coherent.
One new tool for fighting academic isolation that I would suggest might be to find a sense of community online, by blogging the dissertation. It might sound anti-intuitive; several humanities scholar-bloggers I respect have argued that blogging under one's own name while still in grad school might do more harm than good. (The same folks have suggested you should watch out as junior faculty too! Oh well.) Perhaps graduate students interested in this track might get the benefit without the potential harm by blogging about their progress in the dissertation under a pseudonym?