That was a different kind, not what Nintendo needed for the Plus.
Most of the current gyroscope techs, including the piezoelectric one used in WarioWare and the tuning fork one used in WM Plus already existed in 2004, they already competed with each other and they were obviously even smaller and cheaper in 2006, otherwise Ninty wouldn't ever have suggested their use as standard equipment in the first WiiMote trailer gumby_trucker kindly linked. There was obviously the decision to go cheaper and furtherly increase initial HW profit, it cashed in early, but it backfired later.
1. It's not just any gyroscope. They needed on that could track full movement in a certain way, and those were the kind used on cars, which were not small or affordable at the time. The first commercial releases that were came out around the time of WSR.
2. And the delay didn't hurt Motion Plus. It was Nintendo making so few games that supported it and therefore showed it off. We got WSR, Fling Smash up until recently. Instead they wanted to show off how awesome they could make cut scenes.
1. Months ago I found some links to manufacturers spec sheets, in 2006 models with the max and minimum angular velocity, minimum rotation detectable and precision needed for motion control already existed. They were obviously not as cheap and small as in 2008, but they already were cheap and small enough to not drag a $250 Wii into loss. (IIRC the model used in WarioWare twisted just fell short of future Ninty needs, but in 2004).
2. About this I partially agree with you: Ninty could have supported it more. But 3rd party support was surely heavily damaged by the vast majority of installed base not having WM Plus feature, this will be changed only if and when Wiis equipped with the feature will exceed those that aren't by a large enough margin. In the meantime, 3rd parties just want to sell SW, pushing HW sales isn't their job, so they'll support WM Plus feature on a small range of titles, if any. Actually they benefit from wider installed base, but they have no interest in tayloring their SW to push speciphic peripherals or features if their SW can sell more if it doesn't depend on them. With their particular needs and due to how marketing works, "a more precise version of WiiMote" doesn't help selling SW as effectively as, for example, Balance Board or Kinect, new peripherals that widened motion control market. Anyhow, WSR did a good, well, I'd say an excellent one to launch WM Plus, but after it 1st party SW to furtherly push its adoption was scarce and sparse. Sony is facing similar issues with PS Move, made worse by it being an even later addition to the base console architecture.
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