I can understand why they don’t put a Linux-specific icon, because there is such a variety of builds and hardware permutations that people could start complaining “it said it could run on Linux but it doesn’t run on my Linux.“

Steam already indicates which games will run on Linux, without any distro or configuration caveats. There’s literally an entire section of the store for “SteamOS & Linux” games, and games that support multiple platforms have the system requirements listed for each of those supported platforms.

We’re just talking about putting the icon for the platform they used on the review, to help you filter reviews that may be more or less relevant. Linux users complaining about Linux related issues aren’t relevant to Windows users for instance, and vice versa. Same goes for the 15 or so MacOS gamers I guess too.