This isn't the decision of some snob of a belletrist. It is the decision of Judge Time, who constantly separates those who last from those who don't. Spoken like a true literary Darwinist. But he's wrong again. Literature isn't a neat little hierarchy like they have in the English departments.
Literature is a universe.
There's a lot of unpopular uncanonized stuff that's good. And there's a lot of popular canonized stuff that's crappy. So don't take any shit from Martin Amis or any other arrogant literary-absolutist. Spoken like a true literary Darwinist. But he's wrong again.