Ray Saintonge wrote:
Speculation is not proof. The "Guinness Book of World Records" has been consistent best seller in the past century, as was Joseph P. Haydn's "Dictionary of Dates" during the previous century. Both contained an enormous amount of trivia.
Other consistent non-fiction best sellers of the past century include Dale Carnegie's "How to Win Friends and Influence People" and "The Better Homes and Gardens Cookbook". Being a bestseller does not make a work instructive as to what an encyclopedia ought to contain.