Shells are made for people to interact with, not for programming. They happen to also be useful for programming, so many things have been added on over time to

Shells are made for people to interact with, not for programming. They happen to also be useful for programming, so many things have been added on over time to support that. Shell scripting is also the least painful way to call many external programs and glue them together into something useful. Calling external programs from “real” programming languages is far more painful. If you need a real programming language, as you mentioned, use something designed for that.