Never listen to anyone who tells you to quit being passionate about literature.
I don’t know what “ulterior motives” beside sharing a love of literature could be when giving book recommendations. Obviously Dumais feels that romance alongside sharing literature tends to leave a bad taste in her mouth. Fine. But I think for most bookworms, following this advice (I assume it’s a two-way street; both sexes not recommending books) would lead to a betrayal of the self, hiding one’s passions and influences. That’s not only unhealthy self-repression but disingenuous to your potential romantic partner.
Dumais isn’t actually telling us to lose our passion for books; she’s saying don’t mix reading with romance. Good advice for dating her. Horrible advice for most men and women who like to engage in good book talk.