I bought it because it intrigued me.... I have never followed with the popular trends because they are popular [playstation] which is why I had a GC. (luckily this time something I already planned to get then became popular)
If you want a full list of why I bought Wii I shall try to make one [relatively in importance order]
1. New intriguing philosophy on gaming [general "Wiiness" of it, which includes the idea of the remote]
2. Potential of the Wii remote.
3. It's Nintendo (games)
4. Price (still the most I've paid for a system though)
5. It's Nintendo (build quality/reliability)
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With the fortuitous ability of hindsight, I would also have added Wii Sports in there between 2. and 3.
I am sure there are many people who are put off by the Wii remote. Most I would argue are just unwilling to try new things or resistant to change... though I will admit some probably wouldn't like Wii controls [once they are not whored out by third parties] even if they tried a wide variety of Wii games, prefarably for a few hours each.