fact is, Who's who is/was also based on user-submitted
autobiographies. The editors made a list of people who "should"
be in there, and sent invitations with a form where the person
could fill in details about family, education, career,
publications, awards, and hobbies. I'm not sure how the editors
fact checked the entries. Perhaps the risk of public shame was
enough to keep people from lying.
What makes you think people didn't lie?