you seem to be conflating "open" and "open source"

nintendo doesnt have to make the switch open source to make it open, they just have to allow people to make whatever the hell they want for it, but their business model depends on it being locked down (closed)

A bit, but I don't necessarily mean open source either. My main point is that people call Steam "open" but they in fact do not allow you to make whatever the hell you want. They are infamously vague about what they do or don't allow and devs constantly have trouble contacting them when they have issues, be it getting a game on the store, enabling steam features, keys, abusive users, etc.

Given all that this doesn't feel like a plea to let people publish their games. Just a thinly veiled port begging.

I think in this thread we’re talking about the Steamdeck being open, not Steam itself. You can run anything on a Steamdeck, it’s just running Arch

The hardware argument makes even less sense though. People in these circles complain so much about native performance, why would they want to install Linux on a Nintendo Switch like the PS3 days?

Even if they could, it wouldn't let them play switch games better. It doesn't solve the clear problem here that is the super technically minded people wanting to play Mario and Zelda in 4k/60.

I was talking about the Steam Deck. When the original is the Switch, the Steam Deck is the most logical comparison. "Steam" is just an app running on top of the Steam Deck, and that app isn't even privileged on the system. The user could remove it if they wanted to.

"Open" doesn't mean "open source" although in the case of the Steam Deck, it is both (not including the Steam application, but as I mentioned you can use the Steam Deck for whatever you want including removing the Steam application, so it's not a requirement or a blocker. I know someone who installed their own Bazzite flavor that has Steam removed and only uses Lutris to install GOG games).

Also Steam Store's requirements are only for games listed in their store. As has been mentioned, this is not a requirement for running on the Steam Deck. This is in sharp contrast to Nintendo.

Not sure why you mention Windows considering how Steam Deck comes with Arch Linux out of the box, and Yuzu runs natively on Linux too ?

Steam =/= steam deck. And even then it's not really playing native Linux games if you argue Linux. Its just emulating (in layman's terms, I know what WINE stands for) where most devs actually make their games for.

Microsoft doesn't seem to care (or it's legally dangerous to care). Nintendo does.

What's happening under the hood (Windows translations layer, etc) doesn't really matter for this comparison of Switch to Steam Deck. It only matters what the user is allowed to do/run on the thing. On Nintendo where it's closed, the user is prevented. On Steam Deck where it's open, the user is not.