Because you seemed to imply that Saints Row was a poor example of publishers ignoring the Wii U and, as already noted, Ubisoft are seemingly an exception to this generality.
Dark Souls 2 was announced after the Wii U was released. As was Madden NFL 25.
Activision has Wii U devkits; and Bungie could have them if they wanted to for Destiny.
Crytek have Wii U devkits; but aren't releasing Crysis 3 because of a lack of business drive. Other games listed have similarly skipped the Wii U because of stated lack of business drive.
You want more examples? Thief 4. Witcher 3. Metal Gear: Ground Zeroes.
This idea that there's a slew of third party support waiting in the wings to rush in and surprise everyone is ridiculous. It's as bad as the "there must be stuff coming for Vita" idea.
About Dark Souls 2, it also isn't confirmed for PS4 (yet at least), knowing how Nintendo has a much better relationship now with Namco I think we have a good chance of a Wii U version of it.
As for Destiny I still find it weird how they showed "My body is ready" in the trailer which is a Nintendo meme and also have a Chain Chomp that seems like it was purposely placed for the video.
So either Destiny is coming to Wii U or Activision/Bungie is trolling Nintendo fans (which would just be mean).
Guess we'll have to see.