The Steam Store displays and recommends non-Linux games while on Linux, regardless of whether or not you have SteamOS + Linux checked on this page.
The point is that it's completely unacceptable to display games on a store when the user cannot play them. All you're going to do is anger Linux users who purchase a Windows-only game by accident. The solution is to stop displaying these unrunnable games to people who don't have the required OS, by checking for the Steam client's reported OS or the browser's user agent string.
Your system information
Please describe your issue in as much detail as possible:
Imgur album describing the problem: https://imgur.com/a/2f1iQ
Reddit thread: https://www.reddit.com/r/linux_gaming/comments/53pk9u/the_biggest_problem_imo_with_steam_and_linux/
The Steam Store displays and recommends non-Linux games while on Linux, regardless of whether or not you have SteamOS + Linux checked on this page.
The point is that it's completely unacceptable to display games on a store when the user cannot play them. All you're going to do is anger Linux users who purchase a Windows-only game by accident. The solution is to stop displaying these unrunnable games to people who don't have the required OS, by checking for the Steam client's reported OS or the browser's user agent string.
Steps for reproducing this issue: