That's why they are backing themselves into a corner here. They are fully banking on all those families with kids jumping on this bandwagon and replacing 3DS with this. I just cannot see that happening.
This is not a device I'd give to kids. Its way too fragile and a traditional protective case isn't going to work with all the attachment nonsense. It doesn't have a built in cover, to force kids to close it. You can't just toss it in your bag or a large jacket pocket. The battery life is abysmal. Dropping it once down the space between the seats in a car could wreck it. It has exhaust ports open to elements. Durability is one of the top things parents value about the various DS product lines. Lose a JoyCon? $50. Each.
Beyond that, it doesn't play 3DS or DS games, so they are asking people to start all over. Just about every parent I have talked to has cited this. It makes no sense to them to spend this much on a new system with such a limited library of broad family appealing games when their kids also now have tablets or are getting smartphones.
What I really think is going to happen here is that yup, it's gonna sell out at launch and depending on how "Nintendo" Nintendo is with craptastix intentional distribution blocks maybe through the holidays. But I think they have made a losing gamble here by risking their 3DS business on this system.
While personally I like the idea of not having franchise games jump back and forth between portable and console and just having them on one platform, the families that make up the vast majority of 3DS owners (who's kids buy all those pony games we turn our noses up at) are just going to be abandoned by Nintendo. They aren't going for hard core gamers, they are pricing this out of casual gamers (1,2 Switch for $60??!!!), it's not kid friendly on any level, and old foogies like me are just burnt on Wii U and tired of Nintendo's antics.
Particularly with the more in depth reviews of the hardware itself, how the controllers feel, etc that is coming out - I think this may be the one that finally does Nintendo in. I love Nintendo. I just can't see how this is going to work. This Millenial audience they are apparently going after is limited, both in interest in gaming systems and finances to afford such a pricy ecosystem. For the price of a Switch, extra controllers, cases, etc and a couple of games you could just buy a new tablet which can play games and do so much more. This audience they are banking on doesn't have the Nintendo brand loyalty to do it "just because Nintendo".