[TorKlingberg]

I guess most people cannot be bothered to remember which features are bash specific and which will work in any /bin/sh. I don't think there is such a thing as a generic "shell script", csh has completely different syntax.

[stephenr]

The generic variant is called posix compatible or sometimes Bourne compatible.

Lots of people target bash without knowing that some of its non-posix features are not compatible across even minor versions.