Anybody creating music within the primarily perceived to be "black" framework of popular oriented music, such as "hip hop" or "R&B," was working against severe institutional racism from the indie scene (actually less so, the white mainstream of Rolling Stone et al, who were semi respectful) prior to the election of Obama. At that point the Pitchforkers kind of belatedly realized "hmmm in all 14 years of our existence and choosing AOTYs every year, somehow we have never declared any non white artist to have made the album of the year, and have never selected any album from any genre whose majority of artists and/or listeners are probably not white or perceived as not white, such as the hip hop genre, which also happens to be the most globally influential and popular genre. wait so we're reviewing music, we're seen as the biggest tastemakers now, and yet we have said the most influential genre, which just happens to be one of the less-white ones, does not matter at all in the end? hmmm. how can we look less racist than we are??"
and into that moment, steps kanye, with a hybrid-genre album that would arguably (just like 808s) not even have been considered "hip hop" a few years earlier (like when nas declared the form dead in '06). pitchfork benefited themselves by giving kanye a 10.0. it was their "look i have a black friend" moment.
mbdtf is certainly overrated in the sense that it is nowhere near the best hip hop album ever (especially since it isn't a hip hop album, anymore than Kid A is a "rock" album). It does not deserve to be the first album by a hip hop artist pitchfork ever declared AOTY, and still the only album by a hip hop artist (or indeed a non-white male artist) pitchfork have ever declared 10.0 worthy on its initial release (yes, shockingly even TPAB got a 9.3, the same score as fucking Shields by Grizzly Bear and Bloom by Beach House).
Another thing working against Kanye (unlike Kendrick) is that he was also working in "pop" (he described "pop art" as the genre of 808s and was planning a co headlining tour with Gaga before the VMA incident- 2007-9 hits like Good Life and Flashing Lights and Stronger and Heartless and Paranoid and Love Lockdown helped invent EDM-pop as we know it). and "pop" at least prior to 2010 was implicitly perceived to be a "female" or "queer" framework (in its majority of fans if not the sex of the artists) which meant Kanye wasn't trusted by many hip hop heads (including many black males) as "real."
Kanye- more than Daft Punk- essentially invented, in his 2007-2009 work, the commercial style of EDM-pop that dominated the 2010s. This was something that indie fans could only belatedly accept, when merged with rock and even folk aesthetics (I mean MBDTF's Bon Iver guest spot may as well have originally been reserved for the Thom of Give Up the Ghost) and some hints of hip hop "reality."