My point is that Steam doesn’t have to be proprietary. You can make money in an ethical way with Free Software. Itch.io does this by providing a Free Software client. There is no excuse for making nonfree software. I don’t know why they didn’t use BSD like Sony did, but it really doesn’t matter.
If something contains proprietary software, then it’s proprietary. I know that you can turn SteamOS into a Free Software system. At the very least you would have to remove Steam (this is easy), use a Linux kernel without proprietary blobs (might be harder, but Arch has the same issue) and maybe some other things (I don’t know about the drivers). It’s nice that this is possible, but it’s still proprietary by default and that is wrong.
My priority is not for GNU/Linux (or any other particular OS) to get the most users. It’s not the goal of the Free Software movement. The goal is for people to use Free Software and for proprietary software to be destroyed. Valve makes proprietary software, so they are working against us. If your goal is for people to have freedom and control over their devices, you should criticize those actions too. You can do that, while also praising Valve for the good things that they do. Maybe Valve can change and become better, but if not then at least people should be aware of the situation. If you are against proprietary software, then you should understand that Steam being proprietary is bad for us. But maybe you care about features more than freedom - then we probably won’t agree on this.
If your goal is to get as many people using as much FOSS software as possible, steam is your ally.
I want people to eventually use fully free systems. It can be a gradual process, but this won’t happen if we don’t make our end goal clear to people. Companies that make nonfree software won’t do this - they use the term Open Source to avoid talking about freedom and avoid mentioning that proprietary software is bad. So we have to do this ourselves. You can you Steam and SteamOS if you want and at the same time tell people that we can do better than that. That’s all you have to do - just accept that they current situation isn’t perfect and that we can work on improving it.