The WarioWare games seem to be designed to make you look stupid.
You don't really have to 'swing wildly' in most games, but people might just do that naturally in some games, particularly sports. Besides, you won't 'look stupid' if no one is watching you, or if you have people participating with you.

Non-gamers will most likely be swayed by someone demonstrating it for them, instead of randomly seeing it on a shelf and buying it. If the interest isn't there to buy a game system, it won't matter that the controller is 'easier' to use. They just won't care. Nintendo is focused on approachability. The average person would rather pick up a remote (and know how to use it) than an Xbox controller and try to figure out Halo.