PC gamers and steam gamers are often very different markets. Nintendo, for decades now, was about fun, not power. I'm casual gamer, just for fun, and steam deck, while super cool, is certainly not going to replacement my switch.
Seems like something is very wrong with either Switch hardware performance or Nintendo quality control.
Also many switch ports are abandoned by the devs in a very buggy state. This will probably replace my switch and PC. Very excited.
Nintendo charges you money for new copies of each game you want to play on their latest hardware. You can't just pull out your old copy of Super Mario Bros and install it on your Switch.
Hell, I've heard that there are Switch games that have been out since the very beginning of the console that are still full price.
So certainly a lot of switch owners are playing indie games that they could be playing on this device with better performance.
And you can still keep your switch for nintendo exclusives because they've just made it clear that they're not upgrading the switch in a worthwhile way for at least a year.
I would say this is squarely aimed at the existing switch customer base.