I think this is precisely right. And in a related way, the outsize enthusiasm with which he's celebrated is *because* of his mediocrity. It models and exemplifies a pathway to success and celebrity for young people who otherwise fear for their own future and basic likeability.
To wax a little analytic, and borrowing an insight from a friend, it's not dissimilar to why so much pornography involves average or even unattractive men together w/ outrageously attractive (by, as it were, conventional standards) women: the men offer a screen for projection.
That these examples are all about tropes MALE desire and models FOR MEN is precisely the point. The Shapiro phenomenon is deeply gendered, it's a role model for a certain kind of insecure young man who, among other things, thinks sneering is the same thing as being smart.
a compatible way to frame this is to emphasize how the system of "intellectual" stardom that exalts a Peterson or a Shapiro coexists with market precarity for other types of intellectual workers - academics, journalists, etc - which is also felt downstream as anxiety by youth
this is a situation where crankish ideologies, cultish personal philosophies, and weird self-help movements mushroom and, in some cases, catch. Albrecht Koschorke's "On Hitler's Mein Kampf: The Poetics of National Socialism" is really good on this. 
quickened by material precarity, the vector of their appeal is ultimately *not* about "facts" but, ironically, feelings - principally, cruelty. it's hard to read this, particularly on the quesion of sadism, and *not* think of a whole suite of IDW types and RW grifters
