Take Smalltalk. Do I have an object in my image? Yes? Well I can use it. Does it need to do some compilation or something? I have no idea, it just runs my Smalltalk.
Take Python. Do I have the python code? Yes? Well I can use it. Does it need to do some compilation or something? I have no idea, it just runs my Python.
Take C.
Oh my God.
C is portable, and there are portable operating system interface specifications for the system behaviour accessible from C, so you need to have C sources that are specific to the platform you’re building for. So you have a tool like autoconf or cmake that tests how to edit your sources to make them actually work on this platform, and performs those changes. The outputs from them are then fed into a thing that takes C sources and constructs the software.
What you want is the ability to take some C and use it on a computer. What C programmers think you want is a graph of the actions that must be taken to get from something that’s nearly C source to a program you can use on a computer. What they’re likely to give you is a collection of things, each of which encapsulates part of the graph, and not necessarily all that well. Like autoconf and cmake, mentioned above, which do some of the transformations, but not all of them, and leave it to some other tool (in the case of cmake, your choice of some other tool) to do the rest.
Or look at make, which is actually entirely capable of doing the graph thing well, but frequently not used as such, so that make all works but making any particular target depends on whether you’ve already done other things.
Now take every other programming language. Thanks to the ubiquity of the C run time and the command shell, every programming language needs its own build system named [a-z]+ake that is written in that language, and supplies a subset of make’s capabilities but makes it easier to do whatever it is needs to be done by that language’s tools.
When all you want is to use the software.
