You're right, it was called the Steam Machine, my mistake. I honestly don't think it was very influential in pushing Linux gaming forward, it was a first attempt that was ahead of it's time and Valve kept after it.

The market is flooded with various controllers, but they're all basically the same. I think what Valve is going for here is not really a new controller to take the world by storm, but a companion controller to help sell the Steam Deck. In order for it to be a true companion it must match all the inputs the SD had so people don't have to change their bindings. I play the SD docked and I have to say switching between an Xbox and SC depending on the game and adapting my bindings is annoying when it all just works on the native controls.

When Valve made the SC they were starting from scratch and went with an ambitious design, and let's be frank, no one but a small niche of people liked it because they had grown up with thumbsticks and were unwilling to relearn. With the SD they compromised with both input schemes, which I have to say we need to be grateful for. Look at all the SD competitors and they all ditched trackpads to appeal to the general market. Valve could have done this too.

So largely I agree with you, it would be nice to have a SC 2.0, but I honestly don't think this new leaked one will sell all that well. It's just a companion to sell Decks and I'm grateful they are willing to try that.