I grew up playing games like Mario and FF3 (6). Hence my inclinations towards good gameplay over good graphics.
The graphics in those games WERE good state-of-the-art-for-consoles graphics at that time. You're letting your Nintendo Nostalgia cloud your thinking there.
It was popular with EVERYONE.
We actually dusted off the old Wii just a few weeks ago for New Years:
It it is so popular why did you have to "dust it off"?
The reason you had to dust it off was because the Wii is like that Monopoly, Risk or Life set everyone has....that doesn't actually get played that all that often.
Nintendo focused on simple FUN, and absolutely destroyed the much more powerful competition of the time.
There was plenty of simple Fun to be found on non-Nintendo systems, your Nintendo Fanboyism is getting in the way of objectivity.
Nintendo made a lot of money by convincing non-gamers to buy Wii's...who played some Wii Play or Wii Fit now and then...but mostly the machine sat around gathering dust. And yes, Nintendo sold a lot of Wii's, but other than the minority of Smash bros/Zelda/Kart fanboys, those PS3 and Xbox 360 owners actually USED their systems.