Because they were not even a little bit good
The Legend of Zeldais regarded as one of the best franchises in gaming, but there are some black sheep in the family. Specifically, the Phillips CD-i titlesLink: Faces of EvilandZelda: The Wand of Gamelonare held as embarrassing black eyes on the franchise, as they are ridiculously terrible. In fact, some people find it easier to disassociateZeldawith the CD-i installments altogether.
One such person isLegend of Zeldadirector Eiji Aonuma. Speaking withMTV Multiplayer, Aonuma did his best to distance Nintendo andZeldafrom those titles. He remarked that Nintendo doesn’t consider the CD-i projects to be part of theZeldacanon, and that “they don’t really fit in.”
It’s rare that a Nintendo employee would comment on these games, as the company has typically remained mum on the topic. However, their blatant omission from theHyrule Historiabook probably says more than enough about how Nintendo really feels about their existence.