Nintendo have been pretty much been releasing highly memorable and praised games year-on-year. Most of which have a big designer behind it or at least providing advice, whether it's Miyamoto, Sakurai, Aonuma or whoever.
But of course, times are changing. These people have been in the industry for decades. A new generation will need to take its place so they'll gradually move into coaching roles to pass on their knowledge and experiences.
Also, most games developed by large companies are hardly ever attributed to a single person. It's a lot more collaborative now as studios get bigger and more people are involved compared to back then (where most well-known designers got their popularity from) when it was couple of developers writing assembly.
Probably because it doesn't feed into the
narrative he's trying to make.
Right, that's my point: Miyamoto undermines the thesis of the article.* Mario
* Luigi
* Peach
* Bowser
* Donkey Kong
* Link
* Ganondorf
* Zelda
* Fox McCloud
* Olimar (and Pikmin)
He's still around and is one of the major players of Nintendo. Another major figure is Masahiro Sakurai, who was the creator of Kirby and Super Smash Bros.
Unfortunately, Miyamoto is spinning down his work and involvement in Nintendo.
[1] http://www.newyorker.com/magazine/2010/12/20/master-of-play
That would never happen though because Nintendo has built him up too much as the mastermind behind everything they ever did. He's part of their company identity now.