This stuff is just unproductive harrumphing about pop culture. Yes the claim about Jay-Z being a “literary god” is a probably well-overblown claim. But to suggest that the artefacts of modern popular culture have no basis or merit as object of study by the relevant scholars is just a reactionary re-assertion of high/low culture divide stuff.
Otherwise what’s the point of studying, for example, Popular Culture in Antiquity? After all, it’s “popular culture” not the stuff that’s been transmitted to us via the Canon of Classical Literature; “If its not Vergil, what’s the point?”. Same sorts of divisions about cultural “worth” and I’m not so sure it would go down well telling all those archaeologists and historians who do Roman Social History and so forth that their scholarship is worthless because its not The Canon. Or is it as historians we only think that worlds long dead to us are the only ones worthy of scholarship, and that the contemporary world is by definition, devalued? Nonetheless all are unconvincing arguments.