The Making of the Atomic Bomb is a classic, award-winning and relevant book. It's exactly the sort of thing a good community library should have, even if it circulates less than Danielle Steel. There is a big difference between what's important and what's popular.
Those Danielle Steel might provide some entertainment and comfort to people (nothing wrong with that). But The Making of the Atomic Bomb could launch a career or a movement, and possibly even -- we can only hope -- save the planet from destruction.
Truly obscure and unimportant books should of course be culled from circulation in a small community library. Their place is in research libraries, etc. But community libraries serve many purposes, the most important of which, in my mind, is to educate and facilitate discovery and personal growth.
Sometimes you have to give people what they don't know they need yet, not just what they think they want right now.
“A library outranks any other one thing a community can do to benefit its people. It is a never failing spring in the desert.” -- Andrew Carnegie
I don't think he was talking about romance novels.