There is a continuum between the possibilities of a programming language and the possibilities of a configuration file. As soon as one says that a programming language is suitable for a particular purpose one has moved a few steps towards the configuration file end of this continuum.
This is, of course, a personal preference but I very much prefer to enjoy the power of programming language as opposed to the lack thereof of configuration files. Therefore, I like programming languages that attempt to be useful for any purpose. My favorite language is still C++ and if I were to switch to something else I would be inclined towards Rust.