There is exactly one such reason: programmers. Python programmers were given operator overloading, and did a good job with it. C++ and Scala programmers were given operator overloading, and did a bad job with it (eg << in C++'s streams, ^ in Scala's specs2).
I have never heard a convincing theory of why some language communities were careful in their use of operators, whilst others went overboard. In the absence of such a theory, it's a risky feature to add.
Well, it's time to disallow functions, since someone can misuse their names. And exceptions, since someone might use it as goto. Might as well get rid of non-primitive types, there might be a very bad person willing to name a class with a completely meaningless name.
I have never heard a convincing theory of why some language communities were careful in their use of operators, whilst others went overboard. In the absence of such a theory, it's a risky feature to add.