Your individual points are hit and miss: "Gamers that were never gamers" aren't just "old people", for example.
"But by the time Nintendo began to compete it was too late" This is completely backwards. Nintendo started strong and continued for the first 4 years. 2011 is when the Wii really became a unanimous disappointment, which is consequently when it started being outsold on a regualr basis. So yeah, it has become a disappointment since the stellar holiday it enjoyed in 2010; not because it's a "gimmick", but because Nintendo abandoned it.
I agree that for a market leading console, the Wii is a bit of an enigma. Obviously the system missed out on the vast majority of 3rd party hits and Nintendo really let it die a slow death. But the system still amassed a very strong library with many great and unique games, and when you consider other things (such as the wonderful Virtual Console), I will certainly remember it as a great system.
