In reality, it's likely a self-preservation move. Microsoft made what appeared to be a monopolistic move to control the entire Windows ecosystem when they added their own app store and the locked down S edition of Windows. If Valve both hadn't invested in Linux and Microsoft hadn't halted going down that path, they would have been screwed.

steam on linux was officially launched because gaben said windows trying to build a walled garden can go fuck right off. and he was right on the mark; as microsoft keeps buying big studios and locking down their ecosystem more and more. steam going linux and the steam deck are direct responses to wrangle control out of microsofts hands - and with all rights, considering the debacle of directx when that launched and pushing gaming to make hardware development a priority which in turn made microsoft licenses sell for new computers.

Let's also not forget how absolutely groundbreaking Steam was for digital distribution.

I really have a hard time accepting that they "pushed" the industry rather than that they offered a platform with features that were worlds beyond what was available at the time for game developers and publishers. No one was bribed. There were no shady backroom deals. No assassinations of competitors (in fact the opposite, doing experiments with cross platform purchases with the PS3 and with GOG). There was no embrace extend extinguish, as there was nothing already existing like it to embrace or extinguish.

Also saying that they are now supporting linux and open source is ignoring a long history of their work with linux. This isn't something new for them. What's new is yet another large step forward in their investment, not their involvement.

Look, like you, I am concerned about their level of control over digital distribution game sales for the PC market. But from a practical standpoint I find them incredibly hard to have any large amount of negative feelings about them due to their track record, and the fact that they are not a publicly traded company so they are not beholden to the normal shareholder drive for profit at any cost. I'd love to hear more reasons to be concerned if any exist rather than "proprietary" and "too big".

On top of that, Steam DRM is pretty notably easy to bypass, with what appears to be relatively little effort from Valve to eliminate the methods. They aren't doing the normal rat race back and forth between crackers and the DRM devs that you would expect.

Anyway, again I'll say: I'd love to hear more reasons to be concerned beyond "proprietary" and "too big".