I feel this device is too "on the nose" for what PC enthusiasts want. Its a Nomad, not an iPod. Its a Game Gear, not a Gameboy. Enthusiasts will just shrug at its lackluster performance and tiny screen vs just paying a bit more for a gaming laptop or desktop with several times the performance.
I also don't like the idea that if you want to play many popular games, especially those beholden to anti-cheat systems, you have to run Windows and now you have to go through the hassle of buying a Windows license and installing it on this machine. A lot of kids might be disappointed when their parents buy this and they find out they can only play stuff that works on Linux and that stuff may not include the big AAA shooters they want to play (mostly due to anti-cheat being windows only). Worse, Win10 costs $120, which is a pricey upgrade for a device that starts at $399.
I think its often in technology that the customer doesn't know what they actually want. They don't actually know how to ask to be surprised or what that surprise might be, afterall its a surprise! So they just ask for slightly better or tinier versions of the things they already own, which may or may not be the right answer.
Products that actually get successful tend to surprise and break expectations and introduce new concepts. This device just seems like its not doing any of that, but on paper its what PC enthusiasts claim they want, but I'm guessing won't actually buy. I don't know what its EOL will be, but its definitely going to be a super-super niche device, at bit like how Android tablets with things like full size USB slots were seen as potential iPad killers just a few years ago, but failed to get any real marketshare. You can still get an Android tablet, but its just a lackluster device compared to the competition and super-super niche. This device may also have a very long life as potential ammunition against Microsoft trying to seal off Windows from gaming again. It'll always be in production even as a loss because its so politically and economically important to Valve to be able to keep MS from locking them out with the MS store.