At end all comes to 3rd party not to Nintendo, and fact is that most of 3rd party thinks that Switch is more subtitle for last gen AAA ports, this gens AA and smaller games, than for this gens AAA games. I know you want new AAA 3rd party games and not ports of old, but power of Switch is that even ports/remasters of older great/strong games are making huge hype and making Switch even more desarible product.
With 3DS Animal Crossing is become big system seller even in West, on Switch will be even stronger and probably be best selling Animal Crossing game (15m) and huge system seller game.
It's not just me who wants new games.
When people buy a new system, they don't spend 300-400 dollars or euros to play old games or games that they can buy on their older systems.
" 3rd party thinks that Switch is more subtitle for last gen AAA ports"
It's not really a question of thinking, it's reality: Switch can't handle the top games. On some cases, like Doom and Wolfenstein, they can, due to the engine, but in most cases, Switch isn't getting more because it just can't.
Yet, that huge hype, as you call it, isn't translating into huge sales, is it? As the best selling 3rd party game happens to have Mario and company on it. A coincidence.
Also, the top 2 best selling 3rd party games (Skyrim, Fifa and Bomberman) were either revealed before/at launch or lanched with the system. Another coincidence?
As great as it is having hype on your side, it won't necessarily make a difference.
AC sells a lot of SW? Yes.
Does it sell a lot of HW? Yes and no.
I checked sales for 3DS in Japan and the game helped sales a lot. Not just on launch, but also after (i checked 2 to 3 weeks, can't recall how many).
In the US and Europe, it did spike sales at launch, but the next week, sales took quite a dip (only checked 1 to 2 weeks).
So, is AC a system seller outsider Japan? Yes and no.