> making devs lazy when it comes to developing native ports

Is this first order thinking? Whereas second order thinking might be "with Proton enabling an order of magnitude more users that enjoy PC gaming to move to Linux, studios might consider improving the PC gaming experience further with more native ports/testing directly on Linux?"

I don't know if that's how things could play out, but it seems logical to me.

Because Proton creates a dangerous market pressure. The linux+proton user is the ideal customer for a game developer: someone paying full price but to whom you owe absolutely no obligations. Bug reports from Proton users can be safely ignored. They should feel lucky if the game even started under their not-supported hack of an operating system. But those who purchase a native linux client (KSP, Factorio, Prison Architect etc) have to be offered at least a modicum of support.

I like proton. I really like being able to play subnautica. But every time a game updates I cringe a little because I know any new linux-related bugs are more my problem than theirs. I would much rather have game developers treat linux users as full customers.

It does create a dangerous market pressure, but entirely by accident. Valve has developed an amazing piece of software in Proton and made it freely available, but offered no support for developers. Proton is an enormous library papering over an equally enormous API gap between Windows and Linux. Normally when game developers use such components (like engines) they pay a licensing fee, so that when something breaks, if it’s the licensed component’s fault, they can expect support in fixing issues. Since Valve doesn’t offer a paid support option to devs, they are in a difficult position - Proton is by far the easiest way to get games running on Linux, but can’t be officially supported without incurring the cost and overhead of bringing on a team of Proton specialists to ensure compatibility.

I’m not in this area professionally so maybe I have a few things wrong here.

Proton is not a ground-up valve product. It is an implementation of WINE, a project that has been around for a long while. Valve made it pretty and easy to use, integrating wine into their launchers, but it isn't entirely their project.

https://github.com/ValveSoftware/Proton