The Wii offered a lot to the video game market. Why do you think "casual gamer" was coined? lol
All I'm saying is Nintendo could have tried and make a new system from scratch rather than to "fix" all the Wii's problems. They couldn't even help but include "Wii" in the system's name!
They included the name Wii for the exact reason you said above. It's instantly recognizable to the millions of people who never touched video games before the Wii.
And if you've watched the press conference Iwata explained that the Wii U is still a system for everyone, like the Wii was, but is also capable of catering to the individual. Thus the 'U'.