It's not that difficult to test for bashisms (most such scripts fail immediately if run from anything other than bash, often with a syntax error), and honestly,

It's not that difficult to test for bashisms (most such scripts fail immediately if run from anything other than bash, often with a syntax error), and honestly, most of the scripts I've encountered in the wild that specific /bin/sh work well with a sh-compatible shell. This is especially true if they target systems that don't ship with bash by default (*BSD). I think the objective here is that the script authors should request bash when using bash syntax extensions and sh otherwise.