Well I skipped the Wii and Wii-U, so this is where I double-dutch back in. I'm also quite happy they're re-releasing Mario Kart 8 for that reason, and I hope they do the same with other high-profile titles of the past several years.
My little brother finally got a Wii-U this past Christmas, and while they do some interesting things with the second-screen aspect, I got to see just how clunky that gamepad is. It's terrible for controlling games on the TV AND there were several things we couldn't do because the many Wiimotes amassed in that household over the years were never upgraded with Motion Plus.
I believe that Mario Kart bundle was also $300 or near to it, so while it did come with the game, it would have also needed Wiimotes and nunchuks if we didn't already have them. The Switch is far more functionally complete out of the box, and if you need more than two-player support you can get a pair of motion-sensing controllers for the same price it used to be for one (Wiimote + nunchuk combos were still $60 when the Motion Plus add-on launched for $20).