It’s marketing. Nintendo deliberately under stocks new hardware to make the value of the device explode on the secondary market. Scalpers know this and usually buy out most of the first run. When you can’t get the new Nintendo device because it’s unavailable and scalpers are selling it for 2-3x retail price, you are far more likely to buy is asap when it comes back in stock. They make less money initially but in a way that makes the value of the product extremely high, giving people extremely high motivation to buy while they can. Also, a sale to a scalper is worth as much to Nintendo as sale to a consumer. Nintendo is notorious for doing this every time.