@ReaperExTenebris Your assessment of his error with Wii's casual focus is correct, however it's one he already recognized and acknowledged himself. I don't have the actual quote handy but from recollection it was something to the effect of "It was, perhaps, a mistake to focus so much on the casual audience" - from around sometime during the WiiU's signs of deeper slump. So while you're correct he made a mistake, he's already years ahead of you in pointing it out. Keep in mind Switch is mostly a product of his leadership as well. Iwata's final Nintendo console - he'd successfully countered the mistake, and we're holding the result now.

@RAMYERSELL Yamauchi was an astounding, if ruthless, businessman. He was one of the first business leaders to establish a (exclusive!) contract with the interim government post-WWII, after all, long before the Famicom. But in terms of "the game industry" he himself was very much aware he basically had no idea what works and what doesn't. It was just "product" to manage to him, which is why he specifically named Iwata his successor, he wanted someone that actually understood the development and could work with that part of the company better than he could. Iwata, Miyamoto, etc. were brought on by Yamauchi's business sense and ability to size people up for a role, but even while he was running the company, it was they, not he, that really made Nintendo "Nintendo" - he was all numbers and personnel, without much direct involvement with the products themselves.

@BlueOcean When it comes to the handhelds, Nintendo has never failed yet. The closest they came was the launch price of the 3DS which they handled smoothly. Can't fault him for GBA, DS, 3DS, Switch. For home consoles you have to look at it from the perspective of the time. Yokoi, their designer had died. Their console sales were on a continuous downward spiral in sales, and former partner Sony had just annihilated their prior arch rival, Sega two generations in a row, before finally forcing them to close (hardware) shop. VirtualBoy was a dismal failure. SNES did worse than NES. N64 did worse than SNES. GameCube was a total failure just shy of WiiU level failure. What they were doing was NOT working, and Sony was steamrolling the market. They needed to do "something" different. You don't just keep releasing iterations until they get shoved in clearance bins and burn the buyers. If they couldn't do the same thing in the same market they needed to do a different thing in a different market. Thus, Wii. And it was an unprecedented success that had even Sony trying to imitate it. They made some errors with it and could have "ate their cake and had it too", but didn't. But there's really nothing to fault there. Business-wise it was the absolute ideal choice. Market wise, they reinforced the brand, the name, and the IP. They alienated some former customer base (a shrinking customer base) and shouldn't have, it hurt them later, but they did great with what they could do. WiiU is a case study of wrong product at the wrong price at the wrong time. Some of that was self inflicted, some of that was hoping the Wii could continue despite smartphones, and some of that was probably unavoidable confluences of timing, tech, and events. I think Switch ( know you don't like it...most of us do like it ), is kind of final proof that he had his finger on the pulse of the market the whole time, and realized the errors and how to attract the right market. The marketing may not be tied to him, but the product is all him. DQXI was signed on with him. He knew what audience this was going to attract - and he was spot on!