my take on it
I'm inclined to think that, for better or for worse, people will still read Stephen King decades after some of our tonier "literary" authors have been forgotten. Consider the case of James Gould Cozzens, Pulitzer prize-winner, considered a "major" American novelist in the 1940s and 1950s; today nearly forgotten and, so far as I can determine in a cursory search, entirely out of print. Then turn your attention to Raymond Chandler, in his lifetime critically derided as a purveyor of genre fiction, whose posthumous stock has risen steadily, and whose entire oeuvre is still in print.
In reading Stephen King I'm generally surprised at how much better he is than he has to be: he's not a lazy writer and I've never observed him to cheat--that is to say, he gives us honest craft, and whether or not you deem his novels "literature" (I probably wouldn't, but neither do I see a chasm between "literature" and "everything else") they are well-wrought of their kind. If he is very far from being an Updike or a Nabokov as a prose stylist...well, he does not attempt that, and I cannot recall any instances of his solid, workmanlike prose ever making me flinch.
Posterity has the last say in these matters, and although I'm instinctively distrustful of this abstract demographic--if I have little faith in the cultural judgments of the postliterate young, how much more must I disdain their eventual progeny!--I'm content to await that verdict. I suspect that it will prove conspicuously kinder than Professor Bloom's airily dismissive abuse. I'd be tempted to add that Bloom himself will be remembered as a bully and as a snob, but for my doubt that he'll really be remembered at all.
cordially,
Die Welt ist alles, was der Fall ist.