people get confused by the "rock" bit in "rockism" - understandably and forgiveably so
it's a mode of argument based on assumptions to do with artistic worth, durability, seriousness, authenticity, significance
the arguments that people routinely make in favour of e.g. Beyonce are completely rockist - for all intents and purposes, they might as well be writing about Springsteen, the way that rockcritics wrote about Bruce in the Eighties. Or Patti Smith.
equally the arguments people make in favour of hip hop, underground dance music, are rockist as well - usually based on ideas of the street, the underground, innovation, rebellion or anti-hegemonic truth etc
nearly all of stuff written about in the Wire is celebrated in values that are congruent with rockism - varying ideas to do with the cutting edge, spiritual adventurism, expressive intensity, the shock aeshetic - although they often have their own discrete genealogies of ideas / attitudes coming out of pre-rock discourses like jazz or the avant-garde. but most of the people at Wire would have come up through rock press during postpunk or Nineties so some of it comes from rockism.
so there are different branches and modalities of "rockism", and at core, none of them really have to do with distorted electric guitars, raw raspy vocals, etc, ie. the most obvious surface signifiers of "rawk"
the true pure "poptimist" viewpoint is to junk all of those value schemes (both the seriousness/worth/lyrical profundity/ craftmanship/raw honesty ideas that apply to Neil young or nirvana, AND the innovation, futurism, challenge, darkness, danger set of ideas, AND the street cred set of ideas)
the true pure poptimist celebrates the manufactured, the plastic, the shallow, the surface pleasure, the glossy overtly synthetic, the disposable... they celebrate the commodified product nature of pop, they favor the specialist division of labour (separation of songwriter / performer / producer, now taken to post-Fordist containerized globalised extremes with different components of a song being made in different studios around the world, teams of song-doctors, producers, engineers, remixers who collaborate without ever meeting)
the true pure poptimist rejects the idea of virtue or significance in any form - all that matters is the consumer's pleasure - the intent of the artist or the context of production (exploitative or whatever) is irrelevant -
in practice though
(and infuriatingly)
your poptimists will do that kind of "shallow/empty is good" transvaluation move when it's required strategically to celebrate-defend something
but will happily revert to the boring earnest 'substance' oriented arguments to defend-celebrate an artist (e.g. Beyonce but many other examples - Janelle 'Tedium Incarnate' Monae is a good example) if it's applicable... even celebrating the didactic, message-oriented stuff done by the woke-r kinds of these artist (Beyonce with Formation, Lemonade etc) that normally they would deride as boring and rockist if done by a rock artist or Wire type conceptronica artist.
they will do the pure-poptimist rhetoric with really plasticky stuff (K-pop) and then shift to crypto-rockist stodge-thinking for other major pop artists in R&B, where they will emphasise the authorial intent, the fact that she (usually a she) does actually write their own songs