Depending on the exclusivity. If the games were on PC but still console exclusive it would've sold the same. If Nintendo puts their games on all consoles there wouldn't be a point for the Wii U in the first place. Which only shows the missing appeal of your product if the only draw is the exclusives on it.
One console less for gamers to buy is a good thing.
Nintendo games on PC ? That would be the least thing they would do. Mobile i can understand since they already on it. I agree with your last sentence tho. But i couldn't careless tbh, since i only own one console and it's all i need. But if you give me an Xbox One, i would gladly accept it :3