Assuming you've been following sales trends since the Wii U entered the market, how is it that you are just realizing this now? It's a little late to be having this epiphany.
Nintendo didn't market the Wii to the elderly with Wii Sports; it was a combination of low price, ease of use/accessibility and the all important cultural trend factor that allowed the Wii to break through to new markets.
All that talk about Blue Ocean strategy came after the fact. I guarantee no one would have even bothered to mention Blue Ocean with regards to the Wii had it not enjoyed the early success that it did. People used that theory to explain the success of the Wii, as did Nintendo, but it wasn't some grand master plan that was pre-conceived while the Wii was in development.
If anyone cares to refute that claim, then answer why Nintendo didn't repeat the same strategy with the Wii U? They tried and failed. Sometimes a product simply takes off within the public zeitgeist as something that helps define a generation (in this case, a hardware generation, which is closer to 5 years); it has very little to do with marketing and PR. At best, the company with said product can ride the wake of their success by continuing to push their successful product, which is something that Nintendo was only capable of doing until about 2010, after which they really had no follow up to Wii Sports and then Wii Fit. Sports 2 and Fit 2 didn't really count; most Wii owners had already stopped using their consoles, or were content to keep using Sports and Fit.
