Zero, Art Barr's scorn for Nas and his opinions of Niki Minaj are completely irrelevant to each other, as they should be. They're quite different topics.
The reason artists like Nas and Common seem to elicit ulta-disgust from some people - myself included - is that they are artists who embraced hip hop as culture, so that they either publicly or implicitly declared allegiance to certain unspoken rules in hip hop, as well as to the notion that an artist
is his work. That's what makes their convenient and prompt rationalizations about selling out more egregious than Modern M.C. 395730. Especially since Nas and Common going pop is part of what paved the way for doodoo pop rap to become an accepted thing, and threw the culture of hiphop into a state of confusion and downright schizophrenia.
I've always felt the same way about Nas - son is unquestionably a legend, period. But it isn't like Mel and Art are reconstructing history to fit their personal sensibilities when they point out how IWW was perceived by a significant number of people. And at the time, rapping over Kurtis Blow's shyt with L-Boogie on the hook was petty much a transparent cheeseball move.
I have no problem with someone liking IWW, but one can like and dislike within context. Just as I can't stand old ass rap fans so stuck in a knee-jerk mindstate that they can't seem to see the talent in any new artists but hail every new release from a burned out bum from 1991 as a return to the real shyt, it's embarrassing to watch people without much understanding of historical context make absolute declarations and dismissals based on what album happened to be popping in their household or apartment complex when they were old enough to finally understand what music was.
There's a worthwhile, informed and maybe even comprehensive way to converse about artists, albums, and history instead of every debate degenerating into a black-and-white orchestra of put-downs. I read people discussing certain older rap records and they assess them without any care for understanding at all. Almost as if they're watching a great Hitchcock film (I'm not crazy about Hitchcock, just using him as an example) but then deciding generic thriller X from 2007 is better because there's color, explicit sex, and the violence looks more true-to-life.
It's one of the reasons I stopped discussing rap on SOHH years ago. Newer interesting artists and older fundamentally significant artists were being discussed in such stupid terms, it wasn't clear to me that the hip hop forum had very many people posting in it who actually cared much about hip hop.