Bakhtin was very trendy in Renaissance studies in the 80s and 90s. I myself don't have much use for him--I agree with you about the dealing in absolutes, so when I was reading Rabelais and His World (http://www.amazon.com/exec/obidos/tg/detail/-/0253203414/qid=1127492926/sr=2-2/ref=pd_bbs_b_2_2/102-7251415-0477765?v=glance&s=books), I kept saying, "But! But!" and scribbling long irritated notes in the margins.

The only bit of Bakhtin I've actually retained is exactly this thing about classical vs. grotesque, because it does what literary theory is supposed to do and illuminates the way that the culture behind the art affects the art.