Give it a bit of time. The thing will sell better than the Wii U because of the name alone, but the fact that it won't have third party support will soon make itself clear (aswell as software droughts).
Though i doubt some of the numbers we are seeing here in vgc. Even if we were to trust it, the ps4 is already outselling it in europe.
Ultimately the Switch is the Wii U 2, it simply has a better name.
Sure, when I look at Amazon, Media Markt and Saturn in Germany (probably the three biggest sellers for consoles here) and all three tell me the Switch is sold out, it's no surprise the console is selling less as it could and also maybe less as PS4.
Also not sure what this is even supposed to tell us. The PS4 in 2017 is also selling as good or even better as the PS4 in 2014. There is no "lulz, the years old PS4 is already selling better as the much newer Switch" because a console can very well sell some years after release as good as some months after release.
And I doubt you looked at PS4 numbers in 2014 and were like "ohh damn, these numbers are a bad sign" but Switch numbers are, obviously...