The only assumption I can make was that BotW was originally a Wii U game, with much more use out of the game pad. I don’t remember the details but Nintendo had a slew of features specific to the game pad. When they realized that the console was struggling big time, they removed lots of those game pad specific features and made it a Switch launch title.
Again, only assuming because of the removal of those game pad specific features.
And that’s four “game pads” in one post. Now five “game pads.” Now six “game pa**ENOUGH**
As for Twilight: I can I only guess that Nintendo wanted a Zelda launch title so they did that mirror flip thing, slapped wii specific controls on it, and got it out the door.