The Wii Remote Plus had gyroscopes built-in, the attachable 'Nunchuk' also had an accelerometers.

The Wii was pretty clearly sold as a Wii sports console, which got people who would never have touched a "standard" console into the market.

The attachment rate was likely lower because of that.

Right, but it's not the main focus in the majority of games. In many games that do offer gyro support, it's usually able to be toggled off. It's not like the Wii where the core of the controllers was pointing them and swinging them around.

I don't remember motion controls being a majority of Wii games either.

A lot of them were played with a Nunchuk to emulate a classic controller (or attached to the actual Classic Controller or Rock Band instruments to play cross platform games).

The motion control that comes to mind beyond Wii Sports were circling the Wiimote to collect things in Mario.

The Wii exclusive Zelda, Skyward Sword, was motion control only.

Even games that didn't require motion controls for basic gameplay still required you to do things like turn the controller around and use the pointer to select options from a menu rather than using the D pad. (I'm thinking Punch Out). I think Donkey Kong country occasionally made you shake the controller.

Yep, Skyward sword vs Skyward sword HD on the switch. Gimmick is still there but not forced on those who don't like it.

Come on, EVERYTHING about the Wii was about moving these like they were your hands in game. Pretty much NOTHING on the switch uses them. On the other hand VR has accomplished the dream of early Wii games like Red Steel https://www.youtube.com/watch?v=ZfNgkhmPPsc