I think Valve have been very careful with where they put their efforts (hardware and software), their scope isn't that broad so much as it needs to have a direc

I think Valve have been very careful with where they put their efforts (hardware and software), their scope isn't that broad so much as it needs to have a direct link to steam. It's similar to why I don't think we'll have SteamOS released by Valve for generic hardware in the foreseeable future, because they're concentrating on their specific usage on the Deck. Going broad means they need to support a whole lot more, and they probably can't tell users "go google it" in a similar fashion to how MS can't shrug off windows problems entirely when they happen for their users. The geeks are perfectly content with using a range of existing distros and there's little gain in adding one more, besides those that want the Valve/Steam brand umbrella to cover even more of PC gaming like they own the platform.