He's not wrong about Clarke though ;D My (not much of a reader) youngest loved Tales from the White Hart. and I don't see Hitchhikers Guide to the Galaxy going away anytime soon, although you can argue that's comedy/fantasy. I do think there are books everyone *should* read. Mostly textbooks.
I love HHGTHG, and I'm reading to my older kid now - I will definitely say it's aged. A number of things I'vehad to stop and explain, either for referring to tech or norms that don't exist anymore, or being satire of British culture and politics of the time that don't match the worldstate he knows.