Just to note, commercial considerations don't preclude something being or becoming a classic or being seen as art. See also, Dracula as well as the Sherlock Holmes stories -- Doyle had bills to pay, after all.
Noticing the large grin on my puss as I scanned the covers, I think maybe Penguin is displaying their tongue-in-cheek -- and that would certainly be consistent with the corporate persona of Marvel -- as well as latching onto a potentially large payday. Penguin has not been allergic to best-sellers or popular literature.
Another point: Great literature, or at least work considered of literary merit, is sometimes grown from the fertilizer of not so great literature. For instance, William Faulkner was a reader of detective stories and I'll bet his enjoyment led to his approach in the novels Absalom, Absalom, Light in August, and Intruder in the Dust as well as to some of the stories in Knight's Gambit (at least one of which was first published in Ellery Queen's Mystery Magazine). See also, Joyce Carol Oates and Michael Chabon, among others. And David Hartwell wrote that Shirley Jackson once told him she owned the entire run of Unknown magazine.
YAP (Yet Another Point): Classic is a much abused word. Classic Coke. Classic cars. Classic classics. Yet for at least a few generations comic books were a gateway drug to reading, maybe especially for boys and maybe especially superhero comic books. In the process themes of teamwork, loyalty and innovation were stressed. The first time I ever heard of antimatter was in a comic book. Pre-teen (I think) I recognized the underpinnings of The Hound of the Baskervilles in an early Nick Fury, Agent of S.H.I.E.L.D. comic book. If you're going to liken superhero comic books to anything, liken them to Penny Dreadfuls or serials or soap operas, where a recurring cast appears being put through their paces time and again. Maybe not great literature, but all things millions of readers (viewers, listeners) are/were addicted to and some went on to read (watch, listen to) more sophisticated works.