Idk why anyone thought this would be a "PC console killer" type of product. Consoles are subsidized because they act as the entry point to closed hardware/software ecosystems. You can't do that with a general purpose PC because it's an open ecosystem by definition.
But there are economic benefits to an open ecosystem. The Steam Machine has a gigantic back catalog of games that can be had for cheap. You also probably already have all the peripherals you'll need for it. And of course they don't charge for online play.
That last part alone makes up for the cost after just 2-3 years.
This is a general purpose PC but it's also designed for Steam. Valve will get back a fair amount of revenue on games sold for usage on said machines. They could sell it with little to no margin (maybe they are doing it) while increasing gaming time and potential revenue. Sure, games can be had for cheap and so far it seems to be profitable.
If they were sell it without margin people would buy it as a general purpose mini-PC.
Spec may not always match your needs. The hardware is tailored for PC Gaming which is dominated by Steam.
TMK Sony and Nintendo don't lose money on console sales.
Sony have admitted to selling the PS5 at a loss during the first 8 months of sales. Even when they announced the $499 disc drive SKU was no longer selling at a loss, they admitted the $399 SKU still cost more to make than it sold for. Things are no doubt different today.
> https://www.pcmag.com/news/sony-says-499-ps5-no-longer-sells...