While games are what sell a console, during its launch period what counts it's the potential. If you remember the PS4 launch, people always joked about it having "no games" or just PS3 ports. They also called it "Remasterstation". Either way, it kept selling. People weren't buying it for the games it had, but because they knew it would have plenty of great games.
While the Switch has few games, people know it will eventually receive all Nintendo franchises and some 3rd parties. They like the hybrid concept, so they are buying it to play these future games.
About the public, I don't know if it's feeding from the handheld public, since it's quite expensive. Maybe former Wii owners are upgrading to it (most likely skipping the Wii U since its concept was pretty much flawed, Switch is basically Wii U on steroids).








