Why Steam on Linux matters for non-gamers

The "app store" model *is* an "unstable" channel. The point of calling the channel "unstable" isn't that it contains unstable software, but rather that the software hasn't been tested together as part of a stable distribution. Putting your app in an app store and telling users to install from there is no different from putting it in e.g. Debian sid. Either way, you're asking them to install software which may be stable on its own but remains unproven as part of a larger system.

> No. It gives you access to the app store which looks like a typical app store, where you only need to grant the right to distribute you application under certain conditions, where you can verify license keys, etc.

Yeah, I can see why proprietary software vendors might want that, but my impression is that most users of FLOSS operating systems prefer similarly FLOSS applications. We don't want "app stores" selling locked-down proprietary applications which fail to grant essential rights and require things like license keys. That's the sort of thing we switched away from Windows or iOS to avoid.