[casey2]

I think most people starting on linux or *bsd (and macos power users) will learn about POSIX long before they start programming. Usually because a shell script they want to run breaks

If you type 'shell' into arch wiki the first line talks about POSIX On my system typing 'man sh' brings up a posix programming manual. On systems with dash the man page refers to POSIX. On Wikipedia linux mentions it all over the place, on unix's page the offical site link is a link to opengroups. Even 'man man' (man-db) mentions POSIX. Oh, and the coreutils info page mentions it right at the start (and 234 times in total) which based on my admittedly poor count is the second most used nonstandard word behind env beating out coreutils/cp/du/cksum/printf/uniq/.

Until we hit the YOTLD users will continue to be exposed to standards.