i didn't read the book or read scott's article (because his writing tends to be affliatively biased, ironically similar to the middle class signaling fussell critiques). but based on some quick reviews/summaries found via search, the simplest critique of fussell is that he's trying to will his class system into being, attracting acolytes through its writing so as to coalesce sociopolitical power for himself. in short, it's self-serving and that makes it unlikely to be enlighteningly representative. people are constantly trying to segregate and one-up each other (around things like taste, a primary marker of class for fussell), and a static class system like his is just not flexible or fluid enough to represent a highly chaotic and idiosyncratic dynamic.
we have entirely too much of this kind of bullshit to wade through already, obscuring and dispersing the entirely-too-few real pearls of wisdom. sure, it can provide fodder for further, genuine consideration, but that seems to be largely eclipsed for most by identitarian cheering/booing.