70% nintendo loyalists is ridiculous. Here are some game sales (from this site) of wii u software. Games every Nintendo loyalists would most likely own.
Donkey Kong Tropical Freeze: 1,4 Mio
Pikmen 3: 1,06 Mio
Xenoblade X: 0,8 Mio
Zelda: Twilight Princess HD: 0,75 Mio
Here you have your "loyalist" Nintendo fans on Wii U. Around 1-1,5 Mio people (10%).
Games like Mario, mario kart and splatoon are mainstream games, that got those high sale numbers.
You are making the assumption that all Nintendo loyalists buy all their games, after all the evidence we seen people write on here oh i baught the Wii U for Zelda lol. They all have different tastes. The ony common between them is Mario
How is Mario, Mario Kart and Splatoon mainstream games? Mario is like the cornerstone of a Nintendo platform. Did we see a HUGE increate in console sales when these launched? NO because the console is dead to the regular consumer. If Mario and Mario Kart were mainstream games more consoles would have sold. The fact is the ocmpetition has a lot more games suited to the regular user that they want to play.