It is because many people suffer from an intellectual inferiority
complex. They do not trust that their own judgement is valid so they wish
to read what others, preferably professional others such as critics or
professors of literature, have judged to be good and valid. If something is
for kids or from a 'lesser' genre like sci-fi, fantasy, romance or
thrillers, then it is by definition 'inferior' and they are afraid to be
associated with it.
I think so too. Having been an English Lit Major, I got over it fast. I
read all the "canonical" literature. And then whatever I could my hands
on. It's so subjective. I've learned as much from a romance novel as from
a classical literary novel. Or a science fiction pulp novel as a literary
But people get very...snobbish about it. There was a weird community on
livejournal several years ago, made up of book snobs. They basically would
only let people join them if they read critically acclaimed and superior
fare. And reamed you if you didn't propose the right books. And I've seen
this snobbery in reviews on Amazon and Good Reads as well.
It's not unlike the Television snob, who says, in a bragging tone, I never
watch television, it's beneath me. And I think that compulsion does to an
extent come from a superiority/inferiority complex of sorts. As if what we
read or watch defines who we are or is something to brag about?