> The day they actually support native Linux games
They do, and have for a long time now, for nearly all of their own releases. There's not much more they can do than that; they don't control what platforms other companies want to port to.
Sorry, but are you saying you believe Valve is responsible for the development of every game on their store? In case you're just genuinely unaware, games are developed by a variety of people and studios completely separately from Valve.
Yes, and they opt to sell video games from most anyone who opts in to their store. Fundamentally, that is their business. What you're asking of them is beyond unreasonable because it fundamentally goes against what they do and it would immediately kill their business in its entirety if they stopped selling 99% of games. Then we wouldn't even get Proton and Linux would be truly dead for gaming.
What you're asking of them is akin to complaining that Apple sells tech instead of dishwashers when fundamentally that's so far from what they do that it's absurd, not to mention that if they suddenly stopped selling all tech their business would obviously die. I feel a bit foolish for even entertaining this because what you propose is so obviously outlandish to me that I'm about 85% sure you're just messing around to get a rise out of people.