On the other hand reliance on bash-specific features is a net negative for GNU/linux. The most used shell in *nix land is bash, but bash is significantly bigge

On the other hand reliance on bash-specific features is a net negative for GNU/linux. The most used shell in *nix land is bash, but bash is significantly bigger than POSIX. This in practice means that many shell scripts are more bash-compliant than POSIX compliant. It is part of the reason why it was good news when ubuntu/debian decided to transition to dash.