Much like the Wii Motion Plus made the Wii Remote able to do what most people thought it was always supposed to do, the Switch is what people think the Wii U is once they stop thinking it's a Wii peripheral.
I feel like this image conveys what the Switch is really well -- you can play this big full console game on your TV, and also turn it into a tablet and play it anywhere. Maybe people will get confused and think they snap onto a tablet you already have?
It's really good that it's not a Wii or a DS. Those sold really well last decade, but their naming schemes have gotten way too convoluted for the average consumer (New Nintendo 3DS XL in New Galaxy Purple, or the New Nintendo 3DS (they never came up with a name for the smaller one) or the 2DS which is mostly the same thing, but the Wii U is a completely different thing than the Wii but it uses Wii controllers (I'm betting the Switch will still have Wiimote compatibility because why not if they've got Bluetooth anyway, but they're not going to advertise it)). Also, having a one-syllable console name (and one that's a common word) means you're going to hear "Nintendo Switch" more than you hear "Sony Playstation 4 Pro Slim" or "Microsoft Xbox One S" or "Nintendo Gamecube." With other consoles, using the full formal name makes you sound like a PR guy, but "Nintendo Switch" feels pretty natural to say. That's good for brand recognition.
Also I love that they're called "joy-cons."