Sonic Lost World will not feature online multiplayer for Wii U, but will for 3DS version. Why is no one embracing online multiplayer for this console?

I'm a couch co-op guy, but I've had some great times playing games online with friends as well. Gaming is more fun when you're around like-minded people, and I understand what Nintendo is going for here, but I don't quite get why they (as in the developers) would opt to leave out a feature that …