@Hiku:
Not sure what the point with Iphone sales was...
The arcades have been dead in the west for 25 years already because consoles were arcades at home. The arcades are banning kids coming to play their handhelds for the same reason Mc Donalds and Hesburger, and what others there is, are banning kids that come only to sit and make a mess without bringing any money in.
The social phenomenons are different in the west than they are in Japan. Japan had the hugely successful Monster Hunter, while Wii was phenonemical in the west. In Japan you meet with games (on a public space), while in the west you just meet at people's homes and someone might have the game.
It doesn't matter how many are enjoying the games, what matters is how many people are willing to pay money for your game and how are you going to get your game to people's hands, you need to fight disinterest somehow. It is not an "or" situation, but an "and". Just like home computers and consoles have co-existed for 40 years, it's more likely that mobile computers and consoles will co-exist likewise. This seems to be Nintendo's mobile strategy. For example, because of Pokemon Go, I bought Pokemon Sun and Pokemon Moon with a 2DS for christmas for two of my kids.
Nintendo seems to be interested in trying to solve these issues with the Switch (maybe not the games quality issue). You can play it home or on the go if you choose to, and you're able to get the games in your hands without a cost if someone has the game. Just like the DS download play or playing a multiplayer in your home with a friend (and, I did buy Triforce heroes for two of my kids because of the download play multiplayer, one is a Zelda fan because of Hyrule Warriors).
Gamecube was portable too, which is why it had the handle, it was a little hard to play in a bus or train, though (this may be why it sold so bad). Size isn't any more of an issue with the Switch than it is on any tablet, and Switch is a home console first to replace Wii U, portable console second, while not a direct replacement for 3DS. Besides, if you don't like to play Switch on a train, you can play your 3DS or your mobile phone - this isn't an issue for Nintendo, which is why you see games like Super Mario Run.
I do agree, that the smart devices are more of a threat to your "hardcore" gaming on home consoles, as the values are so similar, which is why Final Fantasy and such are seen on mobile.