To be fair, with all the various ways how shell scripts (not only in bash) interpolate, evaluate, substitute etc., the typical shell language is much, much hard

To be fair, with all the various ways how shell scripts (not only in bash) interpolate, evaluate, substitute etc., the typical shell language is much, much harder to keep safe against code injection than say Python (or even PHP). After all, code injection/evaluation is actually what you want in a shell script, half of the time.